strpos
(PHP 4, PHP 5)
strpos — Find position of first occurrence of a string
Description
Returns the numeric position of the first occurrence of needle in the haystack string. Unlike the strrpos() before PHP 5, this function can take a full string as the needle parameter and the entire string will be used.
Parameters
- 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
-
The optional offset parameter allows you to specify which character in haystack to start searching. The position returned is still relative to the beginning of haystack.
Return Values
Returns the position as an integer. If needle is not found, strpos() will return boolean FALSE.
This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". 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
- strrpos() - Find the position of the last occurrence of a substring in a string
- stripos() - Find position of first occurrence of a case-insensitive string
- strripos() - Find position of last occurrence of a case-insensitive string in a string
- strrchr() - Find the last occurrence of a character in a string
- substr() - Return part of a string
- stristr() - Case-insensitive strstr
- strstr() - Find first occurrence of a string