strpos

Find the position of the first occurrence of a substring in a string

Syntax

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

Parameters

haystack

The string to search.

needle

The string to find.

The needle should either be explicitly cast to string, or an explicit call to chr() should be performed.

offset

If specified, search will start this number of characters counted from the beginning of the string. If the offset is negative, the search will start this number of characters counted from the end of the string.

Return

Returns the position of where the needle exists relative to the beginning of the haystack string (independent of offset). Also note that string positions start at 0, and not 1. Returns FALSE if the needle was not found.

Warning: This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Please read the section on Booleans for more information. Use the identity operator (===) for testing the return value of this function.

Examples

haystack needle | string

<?

$haystack = 'CASEcase';
$needle = 's';

$return = strpos($haystack, $needle);

echo $return;

?>
6

haystack needle | chr

<?

$haystack = 'CASEcase';
$needle = chr(115);

$return = strpos($haystack, $needle);

echo $return;

?>
6

offset | Negative

<?

$haystack = 'CASEcase';
$needle = 's';
$offset = -4;

$return = strpos($haystack, $needle, $offset);

echo $return;

?>
6

offset | Non-negative

<?

$haystack = 'CASEcase';
$needle = 's';
$offset = 4;

$return = strpos($haystack, $needle, $offset);

echo $return;

?>
6

Return

<?

// use identity operator (===) instead of comparison operator (==) to test return

$haystack = 'abc';
$needle = 'a';

$return = strpos($haystack, $needle);

if($return === false)
{
    echo "not found";
}
else
{
    echo "found";
}

?>
found

Internal

stripos

External

PHP

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