PHP substr_compare() function

Example

Compare two strings:

<?phpecho substr_compare("Hello world","Hello world",0);?>

Definition and usage

The substr_compare() function compares two strings starting at a specified starting position.

Tip: This function is binary safe and selectively case-sensitive.

grammar

 substr_compare( string1,string2,startpos,length,case )

parameter	describe
string1	Required. Specifies the first string to compare.
string2	Required. Specifies the second string to be compared.
startpos	Required. Specifies where in string1 to start comparison. If negative, counting starts from the end of the string.
length	Optional. Specifies the number of characters in string1 to be compared.
case	Optional. A Boolean value that specifies whether to perform case-sensitive comparisons: FALSE - Default. case sensitive TRUE - not case sensitive

technical details

Return value:	The function returns: 0 - if the two strings are equal <0 - if string1 (startposition startpos) is less than string2 >0 - if string1 (startposition startpos) is greater than string2 If length is greater than or equal to the length of string1, this function returns FALSE.
PHP version:	5+
Update log:	As of PHP 5.1, negative startpos is allowed.

More examples

Example 1

Compare two strings when the starting position for comparison in string1 is 6:

<?phpecho substr_compare("Hello world","world",6);?>

Example 2

Use all parameters:

<?phpecho substr_compare("world","or",1,2); echo substr_compare("world","ld",-2,2);echo substr_compare("world","orl",1,2) ; echo substr_compare("world","OR",1,2,TRUE);echo substr_compare("world","or",1,3); echo substr_compare("world","rl",1,2);?>

Example 3

Different return values:

<?phpecho substr_compare("Hello world!","Hello world!",0); // the two strings are equalecho substr_compare("Hello world!","Hello",0); // string1 is greater than string2echo substr_compare ("Hello world!","Hello world! Hello!",0); // str1 is less than str2?>