PHP substr_count() function

Example

Count the number of occurrences of "world" in a string:

<?phpecho substr_count("Hello world. The world is nice","world");?>

The substr_count() function counts the number of times a substring appears in a string.

Note: Substrings are case-sensitive.

Note: This function does not count overlapping substrings (see Example 2).

Note: This function generates a warning if the start parameter plus the length parameter is greater than the string length (see Example 3).

grammar

 substr_count( string,substring,start,length )

parameter	describe
string	Required. Specifies the string to check.
substring	Required. Specifies the string to be retrieved.
start	Optional. Specifies where in the string to begin the search.
length	Optional. Specifies the length of the search.

technical details

Return value:	Returns the number of times a substring appears in a string.
PHP version:	4+
Update log:	In PHP 5.1, new start and length parameters were added.

More examples

Example 1

Use all parameters:

<?php$str = "This is nice";echo strlen($str)."<br>"; // Using strlen() to return the string lengthecho substr_count($str,"is")."<br> "; // The number of times "is" occurs in the stringecho substr_count($str,"is",2)."<br>"; // The string is now reduced to "is is PHP"echo substr_count($str,"is",3)."<br>"; // The string is now reduced to "s is PHP"echo substr_count($str,"is",3,3)."<br> "; // The string is now reduced to "si"?>

Example 2

Overlapping substrings:

<?php$str = "abcabcab"; echo substr_count($str,"abcab"); // This function does not count overlapped substrings?>

Example 3

If the start and length parameters exceed the string length, this function outputs a warning:

<?phpecho $str = "This is nice";substr_count($str,"is",3,9);?>

Since the length value exceeds the length of the string (3+9 is greater than 12). So this will output a warning.