The strpos Function

The strpos function returns the position of the first occurrence of a substring in another string or false if the substring is not found. The first parameter is the string to search in, the second parameter is the substring to search for.

By default, the function searches from the beginning of the string until the first match. The start of the search can be adjusted with a third optional parameter - if specified, the search will start not from the beginning of the string, but from the specified position.

There is also the stripos function, which does the same thing, but case-insensitively.

Syntax

strpos(string $haystack, string $needle, int $offset = 0): int|false

Example

In this example, the function will return the position of the first character 'c'. It occupies position 2, since the count starts from 0:

<?php
	echo strpos('abcde abcde', 'c');
?>

Code execution result:

2

Example

In this example, the third parameter is specified, so the search will start from the third position. In this case, the function will find the second 'c' character and output its position - 8:

<?php
	echo strpos('abcde abcde', 'c', 3);
?>

Code execution result:

8

Example

If the substring is not found, the function will return false. If the string is at the beginning, the function will return 0. This can be a problem when comparing using the short form of the condition:

<?php
	if (strpos('http://site.ru', 'http://')) {
		echo '+++';
	} else {
		echo '---';
	}
?>

Code execution result (not what we expected):

'---'

Example

Let's perform the correct check for the beginning of the string:

<?php
	if (strpos('http://site.ru', 'http://') === 0) {
		echo '+++';
	} else {
		echo '---';
	}
?>

Code execution result:

'+++'

The strpos Function

Syntax

Example

Example

Example

Example

See Also