programming in c++ spring semester 2013 lecture 3 programming in c++, lecture 3 by umer rana
TRANSCRIPT
Programming In C++
Spring Semester 2013Lecture 3
Programming In C++, Lecture 3 By Umer Rana
• What is counter?
• What is repeat?
• What is decisions?
Programming In C++, Lecture 3 By Umer Rana
Programming In C++, Lecture 3 By Umer Rana
Assignment OperatorsAssignment operators abbreviate assignment expressions• +=• -=• *=• /=• %=Examples :If a=10
a += 1 or (a = a + 1) output is 11a -= 1 or (a = a - 1) output is 9a *= 1 or (a = a * 1) output is 10a /= 1 or (a = a / 1) output is 10a %= 1 or (a = a % 1) output is 0
Programming In C++, Lecture 3 By Umer Rana
Increment / Decrement OperatorsIncrement operator (++)
Can be used instead of a+=1 or a=a+1
Decrement operator (--)Can be used instead of a-=1 or a=a-1
Example:If a equals 10, then
printf( "%d", ++c );Output 11
printf( "%d", c++ ); Output 10In either case, c now has the value of 10
Programming In C++, Lecture 3 By Umer Rana
Decision Making
Equality operators==!=
Relational operators<><=>=
Programming In C++, Lecture 3 By Umer Rana
Data Flow Diagram (DFD)
Expression
Decision
Process
Show Flow
LoopsTo execute a set of instructions repeatedly until a particular condition is being satisfied.
Three types of looping statements are there1) For Loop2) While Loop3) Do while Loop
Programming In C++, Lecture 3 By Umer Rana
LoopsRequires
1. The name of a counter variable 2. The initial value of the counter variable3. A condition that tests for the final value of the counter
variable (i.e., whether looping should continue)4. An increment or decrement by which the counter
variable is modified each time through the loop run
Programming In C++, Lecture 3 By Umer Rana
LoopsFor Loop
For loop in C is the most general looping construct. In for looping statement allows a number of lines represent until the condition is satisfied.
Syntax of for loop expression:For Loop expression is divided by semicolons into three separate expressions: the “Initialize expression”, the “test expression”, and the “Increment/Decrement expresssion”
for(Initialize counter variable ; Condition ; Increment/Decrement the counter variable)
{ Body of the for loop }
Programming In C++, Lecture 3 By Umer Rana
For Loop DFD
Programming In C++, Lecture 3 By Umer Rana
Initialization expression
Test Expression /Condition
Body of loop
Increment / Decrement Expression
ExitFalse
True
Loops
Programming In C++, Lecture 3 By Umer Rana
Example: Print number 1 to 10 this way:
123456789
10
void main(){
printf (“1\n”);printf (“2\n”);printf (“3\n”);printf (“4\n”);printf (“5\n”);printf (“6\n”);printf (“7\n”);printf (“8\n”);printf (“9\n”);printf (“10\n”);
}
Loops
Programming In C++, Lecture 3 By Umer Rana
Example: #include <stdio.h>
void main(){
int counter;for(counter = 1; counter <= 10;
counter++ )
printf( "%d\n", counter );
}
OutPut12345678910
Loops
Programming In C++, Lecture 3 By Umer Rana
Example of Multiple Statement:
#include <stdio.h>void main(){
int counter, total=0;for(counter = 1; counter <= 10; counter++ )
{ total=total + 1;
printf( “counter=%d, total=%d\n", counter,total );
}}
OutPutCounter = 1 Total = 1Counter = 2 Total = 2Counter = 3 Total = 3Counter = 4 Total = 4Counter = 5 Total = 5Counter = 6 Total = 6Counter = 7 Total = 7Counter = 8 Total = 8Counter = 9 Total = 9Counter = 10 Total = 10
Loops While Loop
While loop in C is the other most general looping construct. The while loop statement executes as long as a specified condition is true.
Syntax of while loop expression:while ( condition ) { Code to execute, while the condition is true. }
while(condition) {
statement(s); }
Programming In C++, Lecture 3 By Umer Rana
Loops While Loop DFD
Programming In C++, Lecture 3 By Umer Rana
LoopsExample
Programming In C++, Lecture 3 By Umer Rana
#include <stdio.h>
void main () {
// Local variable declaration: int a = 10; // while loop execution while( a < 20 ) {
printf(“value of a is %d”,a);a++;
}}
LoopsExample
Programming In C++, Lecture 3 By Umer Rana
#include <stdio.h>
void main () {
// Local variable declaration: int a = 0; char ch=‘a’;// while loop execution
while (ch != ‘\r’){
printf(“Enter a character: \n”);ch=getche();printf(“Entered Character is %c\n”,ch);
}}
Loops
do while Loop do… While loop is checks its condition at the bottom of the loop. A do...while loop is similar to a while loop, except that a
do...while loop is execute at least one timeSyntax of do..while loop expression:
do {
statement(s); }
while( condition );
Programming In C++, Lecture 3 By Umer Rana
Loops
do while Loop
Programming In C++, Lecture 3 By Umer Rana
LoopsExample
Programming In C++, Lecture 3 By Umer Rana
#include <stdio.h>
void main () {
// Local variable declaration: int a = 10; // while loop execution do{
printf(“value of a is %d”,a);a++;
} while( a < 20 ) ;
}
Loops Nested Loop One loop inside another loop . In nested loop the inner loop is executed first and then outer.
Syntax of for Nested Loop:for ( init; condition; increment ) {
for ( init; condition; increment ) {
statement(s); }
statement(s); }
Programming In C++, Lecture 3 By Umer Rana
LoopsSyntax of while Nested Loop:
while(condition) {
while(condition) {
statement(s); }
statement(s); }
Programming In C++, Lecture 3 By Umer Rana
LoopsSyntax of do..while Nested Loop:
do {
statement(s); do
{ statement(s);
} while( condition );
}while( condition );
Programming In C++, Lecture 3 By Umer Rana
LoopsLoop Control Statements:Loop control statements change execution from its normal sequence. When execution leaves a scope, all automatic objects that were created in that scope are destroyed
Programming In C++, Lecture 3 By Umer Rana
break statement Terminates the loop or switch statement and transfers execution to the statement immediately following the loop or switch.
continue statement Causes the loop to skip the remainder of its body and immediately retest its condition prior to reiterating.
goto statement Transfers control to the labelled statement.
LoopsBreak Statements:
– When the break statement is encountered inside a loop, the loop is immediately terminated and program control resumes at the next statement following the loop.
– If you are using nested loops ( ie. one loop inside another loop), the break statement will stop the execution of the innermost loop and start executing the next line of code after the block
Programming In C++, Lecture 3 By Umer Rana
true
false
LoopsBreak Statements:#include <stdio.h> Void main () {
/* local variable definition */ int a = 10; /* while loop execution */ while( a < 20 )
{ printf("value of a: %d\n", a); a++; if( a > 15)
{ /* terminate the loop using break statement */ break;
} }
}Programming In C++, Lecture 3 By Umer Rana
LoopsContinue Statements: continue forces the next repetition of
the loop to take place, skipping any code in between.
Programming In C++, Lecture 3 By Umer Rana
true
false
LoopsContinue Statements:#include <stdio.h> Void main () {
/* local variable definition */ int a = 10; /* while loop execution */ while( a < 20 )
{ printf("value of a: %d\n", a); a++; if( a == 15)
{ a++;
continue; }
} }
Programming In C++, Lecture 3 By Umer Rana
LoopsGoto Statements:A goto statement provides an unconditional jump from the goto to a labeled statement in the same function.
Syntex
goto label
.. . label: statement;
Programming In C++, Lecture 3 By Umer Rana
true
false
LoopsGoto Statements:#include <stdio.h>void main () {
/* local variable definition */ int a = 10; /* do loop execution */ LOOP:do
{ if( a == 15)
{ /* skip the iteration */ a ++; goto LOOP;
} printf("value of a: %d\n", a); a++;
}while( a < 20 ); }
Programming In C++, Lecture 3 By Umer Rana
Quiz• How many type of loops we have?• What is the expression of the for loop?• What is the expression of the while loop?• What is the expression of the do.. while loop?• What is nested loop?• What break statement does?• What continue statement does?• What goto statement does?• What you have to do?
Programming In C++, Lecture 3 By Umer Rana
Assignment # 1Q1. Differentiate between IDE and Command-Line Development System. Explain the program execution process and environment with the help of diagram?
Q2. Explain the following terms with appropriate examples:• Getche()• Printf()• Scanf()
Programming In C++, Lecture 3 By Umer Rana