strpos
Find the position of the first occurrence of a substring in a string
Description
intfalse strpos(string $haystack
, string $needle
, int $offset
= 0)
Parameters
-
haystack
-
The string to search in.
-
needle
-
The string to search for.
Prior to PHP 8.0.0, if needle
is not a string, it is converted
to an integer and applied as the ordinal value of a character.
This behavior is deprecated as of PHP 7.3.0, and relying on it is highly
discouraged. Depending on the intended behavior, 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 Values
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.
WarningThis 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 ===
operator for testing the return value of this
function.
Examples
Example #1 Using ===
<?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";
}
?>
Example #2 Using !==
<?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'";
}
?>
Example #3 Using an offset
<?php
// We can search for the character, ignoring anything before the offset
$newstring = 'abcdef abcdef';
$pos = strpos($newstring, 'a', 1); // $pos = 7, not 0
?>
Notes
Note: This function is
binary-safe.
See Also
- stripos
- str_contains
- str_ends_with
- str_starts_with
- strrpos
- strripos
- strstr
- strpbrk
- substr
- preg_match