strpos
(PHP 4, PHP 5, PHP 7)
strpos — Find the position of the first occurrence of a substring in a string
Description
Find the numeric position of the first occurrence of
needle in the haystack string.
Parameters
-
haystack -
The string to search in.
-
needle -
If
needleis 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, theneedleshould 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.
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 ===
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
?>
See Also
- stripos() - Find the position of the first occurrence of a case-insensitive substring in a string
- strrpos() - Find the position of the last occurrence of a substring in a string
- strripos() - Find the position of the last occurrence of a case-insensitive substring in a string
- strstr() - Find the first occurrence of a string
- strpbrk() - Search a string for any of a set of characters
- substr() - Return part of a string
- preg_match() - Perform a regular expression match
English translation
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Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-strpos.html
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References
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