web programming - kocwcontents.kocw.net/kocw/document/2014/wonkwang/leehyun... · 2016. 9. 9. ·...

WONKWANG UNIVERSITY

Web Programming

FUNCTION

WONKWANG UNIVERSITY Division of Information and e-Commerce - HCL 2

CONTENTS

User defined function

String related function

Data and time related functions



A function will be executed by a call to the function.

like procedure, subroutine

purpose : modularization and structuralization

format

Function function_name ( parameter-list ) {

statements;

return return_value;

}

ex


User defined function(2)

Function including parameters

A parameter is just like a variable

Parameters are specified after the function name, inside the parentheses

Distinguishing parameters with “,”

ex



Passing parameters with default value

parameter passing by reference



Function with return value

Return result value using keyword return



Conditional function :

In the previous version(PHP-3), before being referenced function, it must be pre-defined

No constraints but conditional definition of function

example of function inside conditional statements

WONKWANG UNIVERSITY Division of Information and e-Commerce - HCL


Function definition inside function

8



ex (with one parameter)

9



Ex with return value

10



Ex for ftp connection

11

format : ftp_connect(host,port,timeout)



Input between the single quotes, double quotes

1. addslashes( ) : function adding backslash ‘ \’ to in front of the possible

conflicts special character in such as DB query, quoted string

Special characters 4: ‘ ‘, “ “, \, NUL (Null byte)

ex: Bean’s Magic

Search script: select * from book where title = ‘Bean’s Magic’

Error occurred (∵special character): ∴ ‘Bean\’s Magic’

12


String related function(2)

2. bin2hex() : convert binary data into hexadecimal representation

4 bits per hexadecimal characters ( ‘0’ ~ ‘f’ )

13



3. chop() : : remove the specified character or whitespaces of the end of a

string

format : string chop ( string str [, string charlist ] )

4. chr() : change ASCII decimal number into a character of string

format : string chr ( int ascii )

14



5. crypt() : return an encrypted string using the standard Unix DES-based

encryption algorithm, or a variety of algorithms available on the system

format: string crypt ( string str [, string salt ])

15



6. echo : used when more than one string to output

format : void echo ( string arg1 [, string arg n …] )

16



7. explode( ) : function for storing string in an array form after separating

the string using a specified delimiter

format : array explode ( string separator, string string [, int limit ] )

17


String related function(7) -X

8.htmlentities() : function for representing HTML entity character, special character, in a string in web browser

format: string htmlentities ( string string [, int quote_style [, string charset ] ] )

quote_style :

charset: character set to converse (default:ISO-8859-1)

18


String related function(8)-X

9.htmlspecialchars(): if HTML entity character in a string, convert like following

format : string htmlspecialchars ( string string [, int qquote_style [, string charset]])

HTML entity character

문자 HTML Entities

& &

“ " ( ENT_NOQUOTES를 지정하지 않았을 때 )

‘ ' ( ENT_QUOTES를 지정했을 때만)

< <

> >

19



10. Implode() : convert each element in an array using delimiter into a string

the opposite of explode()

format: string implode ( string glue, array piece )

ex

20



11. ltrim () : used to remove the spaces or a specified character at the beginning of the string

format : string ltrim ( string str [, string charlist ] )

characters to eliminate

“ “ (ASCII 32 (0x20)):

“\t” (ASCII 9 (0x09)):

“\n” (ASCII 10 (0x0A)):

“\r” (ASCII 13 (0x0D)):

“\0” (ASCII 0 (0x00)):

“\x0B” (ASCII 11 (0x0B)):

21



12.nl2br () : convert strings including newline key into string including “
” string

format: string nl2br ( string string )

ex

22



13. parse_str( ) : process the value of QUERY_STRING format string and generate variable, substitute for the value.

extract the variable and value both, replace each

format : void parse_str ( string str [, array arr] )

ex

23



14. print () : similar function of echo, used when printing string

format : int print ( string arg )

print - arg, always return 1.

24



15. printf( ) : output a formatted string that begins with %

format : string printf ( string format [, mixed args ] )

Formal indicator

%c : dealing parameters in numeric and express character applicable ASCII

%d : decimal numeric

%s : string

ex

25



16. strchr () : return that string after string that matches a specified string

format : string strchr ( string haystack, string needle )

ex

26



17. strcmp () : : return integer value after comparing 2 strings

format : int strcmp ( string str1, string str2 )

str1 is less than str2 : return -1

str1 is greater than str2 : return 1

Str1 is same as str2 : return 0

Caution : case sensitive

27



18. strip_tags () : return a string after eliminating tags in strings containing PHP or HTML tags

19. strlen() : return an integer value of the string length

format : int strlen ( string str )

28



20. strncmp () : compare two strings from the beginning to the certain length of the strings

forma: int strncmp ( string str1, string str2, int len )

21. strpos () : return the first location of specific strings appeared in the target string, the first location returned

29



22. substr() : return a new string from the string beginning at a specified position to the end of a apecified length

format : string substr ( string string, int start [, int length ] )

30



23. trim () : remove whitespace characters at the beginning and end of the string

String trim ( string str )

31


Data and Time related function

getdate() : return the date and time as a specified form of an array

form: array getdate( [ int timestamp ] )

32


Data and Time related function(2)

Date() : formatted date and time string returned

format: string date ( string format [, int timestamp ] )

Directive:

33


Data and Time related function(3)

Time() : function that returns the current time in timestamp format

format: int time ( void )

Checkdate() : function to determine whether a given date is valid

format : bool checkdate( int month, int day, int year )

34


The End



Data and time related functions

web programming - kocwcontents.kocw.net/kocw/document/2014/wonkwang/leehyun... · 2016. 9. 9. ·...

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