TPL2141 - PROGRAMMING LANGUAGE CONCEPT1

1111115155 Lau Jia Quan & 1111115046 Tan Pooi Shiang

Faculty of Information Science & Technology

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Abstract

The purpose of this report will explain the properties about C++ and PHP programming language

to understand their features and advantage on their specific fields. The report conducted to 7

parts which excluded references and appendix. This include the history, basic elements, support

programming style, unique features, current status, application domain and conclusion. Besides

that, this report is also consist as a comparison of the differentiation between C++ and PHP

programming language. This will allow for more individual to understand these two languages.

Lastly, we would like to take this opportunity to show our gratitude to my seniors and diploma

lecturers that give us a lot of suggestion for doing this report, especially to Miss Ong Lee Yeng

that brief us about the details how should be done and what kind of content should be contain in

this report.

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HISTORY OF C++ PROGRAMMING LANGUAGE

The programming language C++ (originally named called “C with Classes”) was created

by Bjarne Strourup, an employee from Bell Labs (AT&T) while doing his Ph.D.thesis in the

1979. At first he had experiences with the language called Simula (a slow language but had some

features that were very helpful for large software development project), which is the first

language that support the object-oriented programming paradigm and found out this paradigm is

very useful for software development. Afterwards, he chose to improve the C language with

Simula-like features to reach his ultimate goal of adding object-oriented programming into C

language which is a language still having portability while having fast speed or low-level

functionality. The first C with Class compiler was call Cfront, which derived from a C compiler

call CPre.

In 1983, the name of language C with Classes changed to C++. Besides that, First edition

of The C++ Programming Language was released,followed by the commercial release of C++

language in the October of the same year.

In 1989, version 2.0 was released of the C++ language, followed by the updated second

edition of The C++ Programming Language in 1991. A lot of new features added in 2.0 such as

multiple inheritance, abstract classes, and static member functions and so on. After the 2.0

update, there was no more any big updates for C++ until now. Just that in 2003 the committee

published a corrected version of the C++ standard.

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BASIC ELEMENTS OF THE LANGUAGE

Name

A name is usually think of identifiers but can be more general. In the C++ programming

language, an identifier is a string of characters, starting with a letter of the alphabet or an

underline. The basic rules in C++ for identifiers are:

1. Only Alphabets, Digits and Underscores are permitted.

2. Identifier name cannot start with a digit and no length limit.

3. Keywords cannot be used as a name. (final, static)

4. Upper case and lower case letters are distinct. (Case-sensitive)

5. Special Characters are not allowed

6. Global Identifier cannot be used as “Identifier”.

Valid Examples

Identifier Note

Howei Capital Letter and Small Letters are Allowed

hue_1 Digits and Underscore is allowed along with alphabets

_ADS Underscore at the first position is allowed

total_of_apple Combine multiple words with underscore are allowed

INT Keywords are allowed but have to change case of any letter

printf printf is allow if not include stdio.h header file

Invalid Examples

Identifier Note

3cars Digits are not allowed in the first letter

Ali^2 Special character are not allow

$friend ‘$’ is not support by C++

John smith Spaces are not allowed in C++

float Keywords are not allowed

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Variables

A variable provide us a named storage for any value that allow programs to manipulate.

Variable can be declared in many ways with different memory requirements and functioning.

Besides that, variable is the name of memory location allocated by the compiler depending upon

the data type of the variable.

Variable must be declared before they can be used. Usually it is advised to declare them

at the starting of the program, but in C++ they can be declared in the middle of program too.

Example:

int main(){ int I; //declared but no initialized char c; //initialized again float I, j ,k; //multiple declaration }

Initialization means assigning value to an already declared variable.

int main(){ int I; //declaration I = 10; //initialization }

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Initialization and declaration can be done in one single step also.

int main(){ int I =10; //declaration and initialization in same step }

If a variable is declared and not initialized by default it will hold a garbage value. Also, if a

variable is once declared and if try to declare it again, we will get a compile time error.

int main(){ int I,j; initialized I = 10; j = 20; int j = I + j; //compile time error, //cannot redeclare a variable in same scope }

Binding

A binding is an association between an entity and an attribute such as between an

operation and a symbol. In C++, binding means the process of converting identifiers (such as

variables and function names) into machine language addresses. Mostly binding are use on

functions. There are two different type of binding, which is static binding and dynamic binding.

Static binding (also called early binding) means that compiler able to associate the

identifier name with a machine address directly. This is mostly used on direct function calls. So

when compiler encounter a function call, it replace the function with a machine language

instruction that tell the CPU to jump to the address of the function. Here is an example of direct

function call.

void PrintResult(int result){ std::cout<<result; }int main(){

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PrintResult(5); //this is a direct function call}

Dynamic binding (also known as late binding) means that some programs may not know

which function will be call until runtime. So in C++, it normally happens when the virtual

keyword is used in method declaration.

Class B{public:virtual void f();

};void B::f(){ cout <<”B::f()”;<<endl;}

In C++ dynamic binding function calls, one way to get dynamic binding is using function

pointers.

int add(int x,int y){return x+y;}int main(){ int (*padd)(int,int)=add;//create a function pointer for add function

Cout << padd(4,4) <<endl; //add 4+4 }

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Built-in and user-defined data type

Each variable has a specific type to determine the size and layout of the variable's

memory, the range of values that can be stored in the memory and the set of operations that can

be applied.

Following are the basic built-in data types in C++:

Basic type of variables in C++

Type Description

bool Store the value true or false only.

int Store integer character

char Character or very short integer

float A single-precision floating point value

double A double-precision floating point value

void Represent absence of type

wchar_t A wide character type

Now we have already know the basic of the C++ data types. But in addition of these, there are

other kinds of user-defined data types.

Typedef, C++ allows us to define our own types based on other existing data types which in the form of: typedef existing_type new_type name;

Where existing_type is a C++ fundamental or other defined type and new_type name is the name

of the new type we going to declare. For example:

typedef double B;typedef int number;typedef char A;typedef char are[30];

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Union allow a portion of memory to be accessed as different date types since all of them

are in the same memory location. It’s declaration form is :

union model_name{ type1 element1;type 2 element2;. }object_name;

All of the elements inside union occupy the same space of memory. It’s size is one of the greatest

elements in the declarations. Example:

union mytype_e{char c;int f;}mytype

Scope

All variables has their area of functioning, and out of that boundary they can’t hold their

value. This boundary is called scope of variable. It’s restrict the variable visibility and usability

Therefore, we can conclude that scoping has to do with the accessibility and usability of a

variable. There are two types of scope which is outer scope and inner scope.

Outer scope are mostly where global variables declared which is often declared outside

of main() function. The benefits for declaring like this is they can be assigned different values at

different time in program accessed by any functions or any class. For example:

#include <iostream> using namespace std; int x; //global variable declared int main(){ x=10; //initialized once cout << x << endl;

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x=15; //initialized againcout << x << endl;} Inner scope is where local variables are declared, which is between the curly bracers and

exist inside within them only. It cannot be accessed in the outer scope. For example:

int main() { int i=20; if(i<20) { int n = 100; //local variable declared and initialized

cout << n << endl; //print 100} cout << n << endl; //error, n not available at here }

Lifetime of a variables or objects

The lifetime of a variables is the location where variables exists as in variables are being

created and destroyed while the program is running. Which mean that programming language

will need to let the program create new variables when needed, also delete them when they are

not needed. Therefore, a variable has a lifetime. After that, there are rules apply on C++ lifetime,

a variable begin to exist when defined and stop to exist at the end of the scope of the variable is

defined. Lastly, Lifetime are apply on local and global variables only but with different

condition.

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Local variables, lifetime of existence start only after its definition and ended when it is

outside of the scope it is in shown in the example below.

float f(float x) { ... CANNOT access any variable int var3; <--------- var3 starts to exist .. var3 accessible { .. var3 accessible float var4; <--- var4 starts to exist

var3 and var4 are accessible } <--- var4 ends to exist .. only var3 accessible... } <--------- var3 ends to exist

Global variables can be define outside of any functions which make lifetime of its

existence start when the program starts and end when program exit shown in the example below.

{ int x; < - - global variable start to exist

int main(int argc, char **argv) { ....< - - x accessible } float f(float x) { ....<---- x accessible } } < - - x ends to exist

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Referencing Environment

Referencing Environment of a statement is refer to the collection of names that are

visible. Inside C++ there is a feature call reference to perform this task. A reference is another

name of an existing variable by using & as a declarations. The variable name or the reference

name may use to refer variable when only a reference is initialized with a variable.

int main ()

{

// declare simple variables

int i;

double d;

// declare reference variables

int& r = i;

double& s = d;

i = 5;

cout << "Value of i : " << i << endl;

cout << "Value of i reference : " << r << endl;

d = 11.7;

cout << "Value of d : " << d << endl;

cout << "Value of d reference : " << s << endl;

Output:

Value of i : 5

Value of i reference : 5

Value of d : 11.7

Value of d reference : 11.7

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SUPPORTED PROGRAMMING STYLE OF C++

C++ programming language support more than one programming style, those styles

included imperative programming, object-oriented programming, functional programming, logic

programming and scripting programming.

Object-oriented programming is supported because C++ view a problem in terms of

objects involved rather than the procedure for doing it. An object is an identifiable entity with

characteristics and behaviours, which mean object represent an entity that store data and has its

interface through functions. Below is a sample example is written in object-oriented in C++.

include <iostream>

class Counting {private :int a,b,ans;

public :int & GetNum1() {

return this->a;}int & GetNum2() {

return this->b;}int & GetAns(){

return this->ans;}void SetNum1(int a){

this.a = a;}void SetNum2(int b){

this.b = b;}void Calculate(char c) {

switch(c){case ‘+’:ans = a + b;break;case ‘-’:ans = a – b;break;case ‘*’:ans = a * b;break;case ‘/’:ans = a * b;break;default;break;

}}

};using namespace std;

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int main(int argc, char *argv[]){

Counting calc;cout << “Calculator\n”;cout << “First number:”;cin << calc.GetNum1();cout << “Second number:”;cin << calc.GetNum2();calc.Calculate(‘+’):cout << calc.GetNum1() << “+” << calc.GetNum2() << “=”;cout << calc.GetAns();

}

Above source code show that there is a class call Calculator and implement its addition

operation. Not only that, the code also extended this class to support other operations like

multiple, division and subtract.

Imperative programming are issuing commands, telling the computers what to do. To

be more specific is to be list of instructions. Upon done performing the instructions the result

will be produced. Below is a loop example.

include <stdio.h>

using namespace std;

int main(){

Int value = 1;While(value <= 3){

Printf(“Value %d\n”, value);Value++;

}}

Output:Value 1Value 2Value 3

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Functional Programming. Besides of providing a huge functions library, main reason is

because C++ recently has a new feature that support Lambda functions. A Lambda function is a

function that you can write inline in your source code, similar to the idea of function pointer.

With lambda, creating quick functions has become much easier. Below is an example of basic

lambda syntax.

#include <iostream>

using namespace std;

int main(){

auto func = [] () { cout << "Hello world"; };//[] means lambda function created

func(); // now call the function}

Logic programming by using LC++ which is a library preserves the expression syntax

of logic programming like Prolog but also added C++ static type checking and arbitrary effect

features. By using LC++, C++ programmers can write declarative, Prolog-like code in C++

programs. Sample codes as shown below.

Here is how we declare the type of functors/relations.FUN2(parent,string,string)FUN2(father,string,string)FUN2(mother,string,string)FUN2(child,string,string)FUN1(male,string,string) FUN1(female,string,string)

Here is how we declare logic variables.DECLARE(Mom, string,0)DECLARE(Dad, string,1)DECLARE(Bro, string,2)DECLARE(Sis, string,3)DECLARE(Kid, string,4)DECLARE(X, int,10)DECLARE(Y, int,11)

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Scripting language was apply on C++ due to the update of C++ 11 that focus on usable

library, value types and other. Using C++ as a scripting language has a lot of advantages like

memory leaks won’t happen, faster than any non-JITted scripting language, every line of code is

clear, understandable and expressive. Below is a sample code that read all lines from a file and

write them into another file in sorted order.

#include<string>

#include<vector>

#include<algorithm>

#include<fstream>

using namespace std;

int main(int argc, char **argv) {

  ifstream ifile(argv[1]);

  ofstream ofile(argv[2]);

  string line;

  vector<string> data;

  while(getline(ifile, line)) {

    data.push_back(line);}

  sort(data.begin(), data.end());

  for(const auto &i : data) {

    ofile << i << std::endl;

  }

  return 0;}

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DISTINCT FEATURES OF C++

What are unique features of C++ that distinguish itself from other languages?

Firstly will be the performance. It’s really hard to think have other languages that can

create a program that is fast in performance. Furthermore, low-level features of C++ let us write

programs interacting directly with hardware so it makes C++ still is kings of embedded

programming. After that, C++ provide powerful abstractions, in particular the ability to write

generic code that is better among Java and C#. All about features makes C++ is a better choice of

developing huge operating system because operating systems are huge programs that need to be

fast and interact directly with hardware. Other than that, C++ has a convenience thing call Boost

library: Boost C++ Libraries. It has a lot of useful tools which make C++ is a useful language.

For example, support for regular expressions. Recently inside C++ 11, there is a new feature call

range-based for loops. It is used as a more readable equivalent to the traditional for loop

operating over a range of values, such as all elements in a container. For a better insight, here

you can find a better understanding about this feature Range-Based for loops.

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APPLICATION DOMAIN OF THE LANGUAGE

What application domain(s) is C++ designed for?

C++ provide a combination of reasonable portability. It offers easy low-level access to

machine like raw memory that supports operating systems and device driver, medium-level

capabilities such as data structuring and modularity like compilers, lastly high-level code-

organization arrangement which is object-oriented, exception handling to help control the

complexity when building large system. So mainly C++ core application domain is on system

programming. Not only that, Application domains that needs interoperability, performance,

deplorability and portability criteria that other programmer-friendly languages failed to

accomplished are C++ best fit in as well.

What type of applications is C++ being used mostly?

From the description above of what application domains that C++ good with, there are a

huge numbers of applications that are developed by C++. Most of the applications are Numerical

computations: graphical games, finance, statistics; Bit fiddling: operating systems, telecom, and

device driver development. Here is a list of companies/applications written in C++ from Bjarne

Stroustrup provide. Most common application that well-known as Adobe System, their major

applications are developed in C++ because it has the effective fast speed to control the huge data

that the system hold. For example, Photoshop and Illustrators. Besides of that, applications that

handles 3D graphics need C++ language due that C++ makes it possible for programmer to

create engines fast enough for their performance in any hard-core graphics. For example

DirectX, Doom III engine and OpenGL. Operating system applications are Microsoft (Visual C+

+), LINUX (CDE Desktop), Apple (IOS kit device drivers) and IBM. There are a few web

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browsers used C++ as well which is Google and Mozilla. Lastly, MySQL the world’s most

popular open source database that contains about 250,000 lines of C++ languages.

CURRENT STATUS OF THE LANGUAGE

Is C++ currently a popular language?

The answer is yes. According to TIOBE, a webpage that accumulate which languages are

being discussed the most. C++ is currently hanging at the top 3 in the chart. Although Java sitting

the first place spot because of Java version 8 gain a great success but C++ is making a big gain

slowly. From a report we found, C++ 14, completed last year has add the ability to handle

Lambdas while inherited from C++ 11 with other improvements that in compilers as helping

language cause. Besides that, Bjarne Stroustrup said that the language’s sweet spot is its ability

to handle complexity while still running fast. Not only that, there are a lot of legacy codes

written in C++. Furthermore, C++ is a flexible languages that work well in applications domains

which from video games to financial applications, categorized as commercial software

development such as desktop programs, database engines, operating system,

simulations(including games), and system software.

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History of PHP

PHP is a programming language created in 1994 by Rasmus Lerdorf. At the first, PHP

was just a simple set of Common Gateway Interface(CGI) binaries written in C programming

language. Rasmus Lerdorf used it for tracking who visits to his online resume, he named the

suite of scripts as “Personal Home Page Tools”, also referenced as “PHP Tools”. In June 1995,

Rasmus going to release the source code for PHP Tools to public which allowed developers to

use it, permitted and encouraged users to provide fixes for bugs in the code.

In September 1995, new implementation included some basic functionality of

PHP such as Perl-like variables, automatic interpretation of form variables, and HTML

embedded syntax. After the implementation it was not entirely well-received. In October 1995,

Rasmus released a cpmplete rewrite code which named as Personal Home Page Construction Kit.

The language was designed like C in structure to make it easy for developers which familiar with

C, Perl, and similar languages.

In April 1996, PHP evolve from a suite of tools into a programming language. It

support for DBM, mSQL and Postgres95 databases, cookies and so on. In 1997 and 1998,

PHP/Fl had a several thousand users around the world. In May 1998, that nearly 60,000 domain

reported having headers containing “PHP”. This number equated to approximately 1% of all

domains on the internet at the time.

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Basic Element of PHP

Names

Name is a string of characters, starting with dollar sign. The basic rules in PHP for

identifiers are:

1. Variable names have to start with a dollar sign($) Example: $variableA

2. Variable names can start with letter or underscore Example: $VAL, $_value

3. Variable names only contain alpha-numeric characters and underscore Example: $VAL, $_value2

4. Variable names cannot start with number Example: $VAL, $_value2

5. Separate variable names by using underscoresExample: $employee_details

6. Variable names is case sensitive Example: $A not equal to $a

7. Values can assigned using “=” operatorExample: $A = 0;

8. Special Keyword can be use as variable nameExample: $return = 0;

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Variables

A variable is a "container" for storing information. Variable can have a short name

(eg: x) or more descriptive name (eg: age).

Declaring PHP variables

Rules for PHP variables:

Variable start with the dollar($) sign, followed by the name of the variable Variable name start with a letter or the underscore(_) character Variable name declared cannot start with a number Variable name can only consist of alpha-numeric characters and underscores (A-z, 0-9,

and _ ) Variable name are case-sensitive ($ACE and $ace are two different variables)

Example:

<?php

$txt = "Hello world!";

$x = 5;

$_y = 10.5;

?>

Assign value to PHP variables

PHP variables can hold several different data types as variable value. Single equal sign(=)

is used to store information in variables.

Example:

$age = 20;

$price = 2.85;

$number = -1;

$name = "Little Brothers";

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Remove value from PHP variables and uncreate PHP variables

To clear out the value from the PHP variables.

Example: $age = "";

To uncreate the PHP variables.

Example: unset($age);

Binding

LATE STATIC BINDING

With the introduce of PHP 5.3, late static binding was introduced. Late static binding can

be used to reference the called class in context static inheritance. Late static binding work by

storing the class named in the last “non-forwarding call”. In static method call, this is the class

explicitly named. In non-static method call, it is the class of the object. A “forwarding call” is a

static one that introduced by self::,parent::, and static::. Late static binding is trying to solve the

limitation of self:: by using static keyword that was already reserved to references the class that

initially called at runtime.

Example: Static Context

<?php

class A {

     public static function who() {

         echo __CLASS__;

     }

     public static function test() {

         static::who(); // Here comes Late Static Bindings

     }

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}

class B extends A {

     public static function who() {

         echo __CLASS__;

     }

}

B::test();

?>

Example: Non-static context

<?php

class A {

     private function foo() {

         echo "success!\n";

     }

     public function test() {

         $this->foo();

         static::foo();

     }

}

class B extends A {

    /* foo() will be copied to B, hence its scope will still be A and

     * the call be successful */

}

class C extends A {

     private function foo() {

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         /* original method is replaced; the scope of the new 

one is C */

     }

}

$b = new B();

$b->test();

$c = new C();

$c->test();   //fails

?>

Since $this-> will calling private method from the same scope, using static:: may giving a

different result ans static:: can only refer to static properties.

Data Type

Variables can store information of different types, and different data types can do

different things.

PHP supported data types:

String Integer Float (floating point numbers - also called double) Boolean Array Object NULL Resource

PHP String

A string data type is a sequence of characters, like "Hello guys". A string can be any text put

between the quotes. You can use single or double quotes:

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Example:

<?php  $x = "Hello world!"; $y = 'Hello world!';

echo $x; echo "<br>";  echo $y;?>

PHP Integer

An integer is a whole number (without decimals).  It can be a number between -

2,147,433,658 and +2,147,423,617.

Rules for integers:

Must have at least one digit (0-9) Cannot contain comma or blanks Must not have a decimal point Can be either positive or negative Can be specified in three formats: decimal (10-based), hexadecimal (16-based - prefixed

with 0x) or octal (8-based - prefixed with 0)

Example

<?php 

$x = 5985;

var_dump($x);

?>

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PHP Float

A float data type (floating point number) is a number with a decimal point or a number in

exponential form.

Example

<?php 

$x = 10.365;

var_dump($x);

?>

PHP Boolean

A Boolean will only represents two possible states: TRUE or FALSE.

$x = true;$y = false;

PHP Array

Array stores multiple values in one single variable.

In the following example $cars is an array. The PHP var_dump() function returns the data type

and value:

Example

<?php 

$cars = array("Volvo","BMW","Toyota");

var_dump($cars);

?>

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PHP Object

Object is a data type which stores data and information on how to process that data. In PHP,

object must be explicitly declared. To declare a class of object, we use the class keyword. A class

can contain properties and methods:

Example

<?php

class Car {

    function Car() {

        $this->model = "VW";

    }

}

// create an object

$herbie = new Car();

// show object properties

echo $herbie->model;

?>

PHP NULL Value

Null is a special data type which can only one value: NULL. A variable with NULL data type is a

variable that has no value assigned to it.

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Example

<?php

$x = "Hello world!";

$x = null;

var_dump($x);

?>

PHP Resource

The special resource type is not an actual data type. It holding a reference to external resource.

The resources are created and used by special functions.

Example:

<?php

// prints: mysql link

$c = mysql_connect();

echo get_resource_type($c) . "\n";

// prints: stream

$fp = fopen("foo", "w");

echo get_resource_type($fp) . "\n";

// prints: domxml document

$doc = new_xmldoc("1.0");

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echo get_resource_type($doc->doc) . "\n";

?>

Scope

Scope of a variable is the context within which variable is defined. Most part of all PHP

variables only have a single scope. Single scope spans included and required files as well.

Local variable

Example:

<?php $a = 1; include 'b.inc';?>

Here the $a variable only available within the included b.inc script. However, the user-defined functions a local function scope is introduced. All variable used inside a function will be default limited to the local function scope. For example:<?php $a = 1; /* global scope */  function test() {      echo $a; /* reference to local scope variable */  }  test();?>

The above script will not produce any output because the echo statement refers to a local version of the $a variable, and it has not been assigned a value within this scope. In PHP global variables must be declared global inside a function if they going to be used in the function.

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Global variableExample:<?php $a = 1; $b = 2; function Sum() {     global $a, $b;

     $b = $a + $b; }  Sum(); echo $b;?>The above script will produce an output of 3. By declaring $a and $b as global within function, all references to the variable will refer to global version.

Static variableStatic variable exists in local function scope, but it do not lose value when program leaves this scope.<?php function test() {     static $a = 0;     echo $a;     $a++; }?>

$a is initialized in first call if function and when test() function called every time, it will print out the value of $a and increase the value by 1.

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Lifetime of a variables or objects

In PHP, a variable will live until the whole page has finished being parsed. If you like to destroy

the $variable, you have to call the function unset() or unset($variable); 

In PHP, the variables in the contents of $_SESSION are retained which means that whenever a

script executes objects and variables are created and upon completion all objects/variables are

destroyed.

For Functions in PHP, there have their own private name space which mean the variables used

within those functions are locally scoped only to that function and are ignorant of any variables

of the same name outside of that function.

Referencing Environment

The referencing environment of a statement is the collection of all names that are visible in the

statement

Local Variables

Variable declared in a function is considered local. It can be referenced solely in that function. Assignment outside of that function will be considered as a different variable from the one contained in the function

Example

<?php

$x = 4;

function assignx () {

$x = 0;

print "\$x inside function is $x. <br />";

}

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assignx();

print "\$x outside of function is $x. <br />";

?>

OUTPUT:

$x inside function is 0. $x outside of function is 4. 

Global Variables - Superglobals

The PHP common superglobal variables are:

$GLOBALS $_REQUEST $_POST $_GET

PHP $GLOBALS

Used to access the global variables from anywhere in the PHP script.

Example

<?php 

$x = 75; 

$y = 25;

 

function addition() { 

    $GLOBALS['z'] = $GLOBALS['x'] + $GLOBALS['y']; 

}

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addition(); 

echo $z; 

?>

In the above script, $z is a global variable so it is accessible from outside the function.

PHP $_REQUEST

Used to collect data after submitting an HTML form.

Example:

<html><body>

<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">  Name: <input type="text" name="fname">  <input type="submit"></form>

<?phpif ($_SERVER["REQUEST_METHOD"] == "POST") {    // collect value of input field    $name = $_REQUEST['fname'];    if (empty($name)) {        echo "Name is empty";    } else {        echo $name;    }}?>

</body></html>

35

PHP $_POST

Widely used to collect form data after submitting an HTML form with method="post" and used to pass variables as well.

Example:

<html><body>

<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">  Name: <input type="text" name="fname">  <input type="submit"></form>

<?phpif ($_SERVER["REQUEST_METHOD"] == "POST") {    // collect value of input field    $name = $_POST['fname'];    if (empty($name)) {        echo "Name is empty";    } else {        echo $name;    }}?>

</body></html>

PHP $_GET

Used to collect form data after submitting an HTML form with method="get".

We have an HTML page that contains a hyperlink with parameters:

<html>

<body>

<a href="test_get.php?subject=PHP&web=W3schools.com">Test $GET</a>

36

</body>

</html>

User clicks on the link "Test $GET", the parameters "subject" and "web" is sent to "test_get.php", and to access the values in "test_get.php" we need to use $_GET.

Example:<html><body>

<?php echo "Study " . $_GET['subject'] . " at " . $_GET['web'];?>

</body></html>OUTPUT:Study PHP at W3schools.com

Support Programming Style

Object-oriented programming

Documentation is organized using the object-oriented interface. The object-oriented

interface shows functions grouped by their purpose, making it easier to get started. The reference

section gives examples for both syntax variants.

Example

<?php

$mysqli = mysqli_connect("example.com", "user", "password", "database"

);

if (mysqli_connect_errno($mysqli)) {

    

echo "Failed to connect to MySQL: " . mysqli_connect_error();

37

}

$res = mysqli_query($mysqli, "SELECT 'A world full of ' AS _msg FROM D

UAL");

$row = mysqli_fetch_assoc($res);

echo $row['_msg'];

$mysqli = new mysqli("example.com", "user", "password", "database");

if ($mysqli->connect_errno) {

     echo "Failed to connect to MySQL: " . $mysqli-

>connect_error;

}

$res = $mysqli>query("SELECT 'choices to please everybody.' AS _msg FR

OM DUAL);

$row = $res->fetch_assoc();

echo $row['_msg'];

?>

OUTPUT:

A world full of choices to please everybody.

Imperative programming

38

 The imperative interface is same with the old mysql extension. The function names differ

only by prefix. Some mysql functions take a connection handle as the first argument, whereas

matching functions with the old mysql interface take it as an optional last argument.

Example

<?php

$mysqli = mysqli_connect("example.com", "user", "password", "database"

);

$res = mysqli_query($mysqli, "SELECT 'Please, do not use ' AS _msg FRO

M DUAL");

$row = mysqli_fetch_assoc($res);

echo $row['_msg'];

$mysql = mysql_connect("example.com", "user", "password");

mysql_select_db("test");

$res = mysql_query("SELECT 'the mysql extension for new developments.' 

AS _msg FROM DUAL", $mysql);

$row = mysql_fetch_assoc($res);

echo $row['_msg'];

?>

OUTPUT:

Please, do not use the mysql extension for new developments.

39

Distinct features of PHP

1. No need to specify data type for variable declaration. It can be determined at the time of execution depends on the value of the variable.

2. Provides cross platform compatibility, unlike other server side scripting language.3. Has set of pre-defined variables called superglobals which start by _. For examples,

$_GET, $_POST, $_COOKIE, $_SESSION, $_SERVER and etc. 4. The name of the variable can be change dynamically.5. Contains access monitoring capability to create logs as the summary of recent accesses.6. Includes several magic methods that begins with __ character which will be defined and

called at appropriate instance. Example, __clone().7. Supports extended regular expression that leads extensive pattern matching with

remarkable speed.8. Since PHP is a single inheritance language, parent class methods can be derived by only

one directly inherited sub class. But the implementation of the traits concept, reduce the gap over this limitation and allow to reuse required method in several classes.

Application Domain of PHP

PHP is a server-side scripting language designed for web development and also used as

a general-purpose programming language. PHP language can also simply mixed

with HTML code and can used in combination with various templating engines and web

frameworks. PHP is usually processed by PHP interpreter, which usually implemented as a web

server's native module or Common Gateway Interface (CGI) executable. After that the PHP code

is interpreted and executed, the web server sends the output to the client, usually in the form of a

part of the generated web page; example, PHP can generate a web page's HTML code, an image,

or some other data. PHP has also evolved to include a command-line interface (CLI) capability

and can be used in standalone graphical applications.

40

PHP applications are geared toward functions that involve database access, such as search

engines, e-commerce and advertising but now they also can be used for inter-browser

communications and games. Social media sites, electronic forums and remote access for

businesses and educational institutions are also the examples of where PHP applications are

regularly deployed.

PHP can be used on major operating systems, including Linux, many Unix variants

(including HP-UX, Solaris and OpenBSD), Microsoft Windows, Mac OS X, RISC OS, and so

on. Besides that, PHP also support most of the web servers today which includes Apache, IIS.

And this also includes any web server that can utilize the FastCGI PHP binary, like lighttpd and

nginx. PHP works as either a module, or as a CGI processor.

Current Status of PHP

In my point of view, PHP is still a popular programming language. According to TIOBE

website, PHP is currently allocated at the top 7 of the TIOBE chart. To anyone who visited the

Facebook, Wikipedia or any WordPress-powered blogs, you are experienced PHP in action. The

web page and the file ends in the extension .php rather than .html, the page you are viewing will

run through pre-processor before served to your browser. It’s not just a common social website

but blogs that heavily on PHP programming.

There are several reasons why PHP is so popular recently. One of the reason is PHP is a

server-side script rather than client side which mean the processing is done on the Web hosts

server, rather than on your machine. So the users can access to the sites such as Facebook from

any computer by entering the username and password to login into their account.

41

Besides that, PHP is an Open Source which everyone can access and edit the source code

and contribute the future development. This also one of the reason why so many plug-in

programs available written in PHP. Because PHP is an Open Source, so there are no licensing

fees to pay to install it which will decrease the cost of running a server.

Other than that, PHP is a platform independent and even runs on a Window server which

mean it is a pre-installed by the majority of web hosting companies on their server which

complete with library script to install on your domain. Finally, PHP is a easy to learn

programming language which mean users can start off with a standard installation of program

and tweak it to meet own specific need.

CONCLUSION REMARKS

Comparison of both languages

From all the works we have done, we conclude that although PHP and C++ programming

languages share the similar syntax and function definitions but they are two different languages

that are served on different purposes. PHP are used for design websites that interact with

databases while C++ creates stand-alone applications. Besides that, C++ is a “compiled

language” that in the compilation progress C++ codes needs to be compiled into binary then

becoming an .exe but PHP as a “interpreted language” can be interpreted directly from the source

by Apache. Furthermore, the biggest differences is PHP has no variable types and C++ is

strongly typed. Which mean every variables in C++ must have a known type at compile time; but

not in PHP that only use a dollar sign($) and have no declared type. More often, PHP has

interfaces and does not allow multiple inheritance while C++ react on the opposite way on the

object system.

42

Opinions

In our opinion, PHP is a simple program language. For all the users, PHP is easy to learn,

easy to write, easy to read, libraries available and easy to debug. Besides that, because PHP is a

scripting language, it has major benefits in terms of programmer productivity and the ability to

iterate quickly on products but scripting languages are known to generally be less efficient when

it comes to CPU and memory usages.Language which are interpreted are much more slower

compare to the compiled languages. This is one of reason why Facebook compiles PHP to C++.

43

References for C++

1. Alex Allain. Lambda Functions in C++ 11 – the Definitive Guide. Retrieved August

29,2015 from http://www.cprogramming.com/c++11/c++11-lambda-closures.html

2. http://oss.org.cn/ossdocs/gnu/c++-tutorial/tutorial/tut3-6.html

3. http://www.mathcs.emory.edu/~cheung/Courses/561/Syllabus/3-C/scoping.html

4. http://www.studytonight.com/cpp/variables-scope-details.php

5. Alex.(2008, Feb 7).12.4 – Early binding and late binding Retrieved August 29,2015 from

http://www.learncpp.com/cpp-tutorial/124-early-binding-and-late-binding/

6. http://www.tutorialspoint.com/cplusplus/cpp_variable_types.htm

7. Brian McNamara.(2003, Aug 22).LC ++ Logic Programming in C++. Retrieved August

29,2015 from http://yanniss.github.io/lc++/

8. http://bytes.com/topic/c/answers/494248-c-shines-what-application-domains

9. http://stackoverflow.com/questions/537595/which-sector-of-software-industry-uses-c

10. http://www.c4learn.com/cplusplus/cpp-variable-naming/

11. https://en.wikipedia.org/wiki/The_C%2B%2B_Programming_Language

12. Albatross.History of C++. Retrieved August 29,2015 from

http://www.cplusplus.com/info/history/

13. http://www.codingunit.com/cplusplus-tutorial-history-of-the-cplusplus-language

14. Navarre Ginsberg.(Apr 30),C++(programming language): What are the features of C++

which most programmers don’t know? Retrieved August 29,2015 from

http://www.quora.com/C++-programming-language/What-are-the-features-of-C++-

which-most-programmers-dont-know

44

15. Jim Dennis.(Jun 20).What is the best features that is unique to that programming

language? Retrieved August 29,2015 from http://www.quora.com/What-is-the-best-

feature-that-is-unique-to-that-programming-language

16. Arne Mertz.(2015, July 19). New C++ Features – std::begin / end and range based for

loops Retrieved August 29,2015 from http://arne-mertz.de/2015/07/new-c-features-

stdbeginend-and-range-based-for-loops/

17. Bartosz Milewski(Aug 23).SafeD Retrieved August 29,2015 from

http://dlang.org/safed.html

18. http://www.boost.org/

19. http://www.equestionanswers.com/cpp-questions.php

20. http://www.programmingsimplified.com/c-program-examples

21. Mathieu Dutour Siiric.(mar 14).Is C++ is a functional programming language or not?

Retrieved August 29,2015 from http://www.quora.com/Is-C++-is-a-functional-

programming-language-or-not

22. http://voices.canonical.com/jussi.pakkanen/2013/10/15/c-has-become-a-scripting-

language/

23. http://www.infoworld.com/article/2947536/application-development/javascript-rules-the-

school-but-c-climbs-in-popularity.html

24. http://stackoverflow.com/questions/1549990/in-which-area-is-c-mostly-used

25. http://www.cplusplus.com/forum/general/16038

26. http://www.quora.com/Is-Java-the-most-commonly-used-language-in-the-software-

industry

27. http://www.stroustrup.com/applications.html

45

28. http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html

29. http://blog.learntoprogram.tv/%E2%80%8Btop-seven-programming-languages-to-learn-

for-2018/

30. http://www.quora.com/Is-C++-still-so-much-faster-that-it-actually-matters-to-use-it-

when-programming-games

31. http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html

32. https://www.quora.com/What-is-the-difference-between-PHP-and-C++

46

References for PHP

1. http://www.w3schools.com/php/php_superglobals.asp

2. Kingfeanor.(2010, March 31).What’s better C++ or PHP? Retrieved August 29,2015 from

http://www.dreamincode.net/forums/topic/165308-whats-better-c-or-php/

3. Kawsar Ahmad.( 2013, Feb 15).What is the difference between PHP and C++?. Retrieved

August 29,2015 from https://www.quora.com/What-is-the-difference-between-PHP-and-

C++

4. Von Vincent Tscherter.(2015, Feb 16).EBNF Parser & Syntax Diagram Renderer.

Retrieved August 29,2015 from http://karmin.ch/ebnf/index

5. http://www.tutorialspoint.com/php/php_local_variables.htm

6. Marc Plotz.(2015).Principles of Object Oriented Programming in PHP. Retrieved August

29,2015 from http://www.htmlgoodies.com/beyond/php/article.php/3909681

7. http://php.net/manual/en/mysqli.quickstart.dual-interface.php

8. Eugene P.(2015, August 01).What are the different Types of PHP Applications?.

Retrieved August 29,2015 from http://www.wisegeek.net/what-are-the-different-types-of-

php-applications.htm

9. https://en.wikipedia.org/wiki/PHP#Implementations

10. http://docstore.mik.ua/orelly/webprog/php/ch03_03.htm

11. Compnerd814.(2008).PHP variable lifetime (confusing). Retrieved August 29,2015 from

https://answers.yahoo.com/question/index?qid=20080706224225AA7hEFK

12. Angela Bradley.What is PHP Used For?. Retrieved August 29,2015 from

http://php.about.com/od/phpbasics/qt/what_is_php_used_for.htm

47

13. Vincy.(2013, April 14).Unique Features of PHP. Retrieved August 29,2015 from

http://phppot.com/php/unique-features-of-php/

14. http://scholar.lib.vt.edu/manuals/php3.0.6/intro-history.html

15. http://php.net/manual/en/language.variables.scope.php

16. http://php.net/manual/en/language.oop5.late-static-bindings.php

17. Neerav Mehta.(2015, Aug 18).Object Oriented PHP. Retrieved August 29,2015 from

http://redcrackle.com/blog/drupal-8/object-oriented-php

18. Gail Seymour.Why Is PHP so Popular. Retrieved August 29,2015 from

http://www.hostway.com/web-resources/how-to-build-a-website/website-code/why-is-

php-so-popular/

48

Appendix

EBNF Syntax of C++

Name Production

abstract_declarator ptr_operator [ abstract_declarator ] direct_abstract_declarator

access_specifier 'private' 'protected' 'public'

additive_expression multiplicative_expression additive_expression '+' multiplicative_expression additive_expression '-' multiplicative_expression

and_expression equality_expression and_expression '&' equality_expression

assignment_expression

conditional_expression logical_or_expression assignment_operator assignment_expressio

n throw_expression

assignment_operator '=' '*=' '/=' '%=' '+=' '-=' '>>=' '<<=' '&=' '^='

More can be found in here : http://www.externsoft.ch/download/cpp-

iso.html#unary_expression

49

EBNF Syntax of PHP

<ebnf> "EBNF defined in itself" {

syntax = [ title ] "{" { production } "}" [ comment ].

production = identifier "=" expression ( "." | ";" ) .

expression = term { "|" term } .

term = factor { factor } .

factor = identifier

| literal

| "[" expression "]"

| "(" expression ")"

| "{" expression "}" .

identifier = character { character } .

title = literal .

comment = literal .

literal = "'" character { character } "'"

| '"' character { character } '"' .

}</ebnf>

More can be found in here : http://karmin.ch/ebnf/index