Find the position of the first occurrence of a substring in a string
$haystack
, mixed $needle
[, int $offset = 0
] )Find the numeric position of the first occurrence of $needle in the $haystack string.
$haystack
The string to search in.
$needle
If $needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
$offset
If specified, search will start this number of characters counted from the beginning of the string. Unlike strrpos and strripos, the offset cannot be negative.
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.
This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Please read the section on FIXME: NEED TO RESOLVE REAL LINK: BooleansFIXME: NEED TO RESOLVE REAL LINK: 1 for more information. Use FIXME: NEED TO RESOLVE REAL LINK: the === operatorFIXME: NEED TO RESOLVE REAL LINK: 2 for testing the return value of this function.
php
<?php
$mystring = 'abc';
$findme = 'a';
$pos = strpos($mystring, $findme);
// Note our use of ===. Simply == would not work as expected
// because the position of 'a' was the 0th (first) character.
if ($pos === false) {
echo "The string '$findme' was not found in the string '$mystring'";
} else {
echo "The string '$findme' was found in the string '$mystring'";
echo " and exists at position $pos";
}
?>
php
<?php
$mystring = 'abc';
$findme = 'a';
$pos = strpos($mystring, $findme);
// The !== operator can also be used. Using != would not work as expected
// because the position of 'a' is 0. The statement (0 != false) evaluates
// to false.
if ($pos !== false) {
echo "The string '$findme' was found in the string '$mystring'";
echo " and exists at position $pos";
} else {
echo "The string '$findme' was not found in the string '$mystring'";
}
?>
php
<?php
// We can search for the character, ignoring anything before the offset
$newstring = 'abcdef abcdef';
$pos = strpos($newstring, 'a', 1); // $pos = 7, not 0
?>
This function is binary-safe.