stripos

    (PHP 5, PHP 7, PHP 8)

    stripos — Find the position of the first occurrence of a case-insensitive substring in a string

    Description

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

    Find the numeric position of the first occurrence of needle in the haystack string.

    Unlike the strpos(), stripos() is case-insensitive.

    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.

    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 === operator for testing the return value of this function.

    Changelog

    Version Description
    8.2.0 Case folding no longer depends on the locale set with setlocale(). Only ASCII case folding will be done. Non-ASCII bytes will be compared by their byte value.
    8.0.0 needle now accepts an empty string.
    8.0.0 Passing an int as needle is no longer supported.
    7.3.0 Passing an int as needle has been deprecated.
    7.1.0 Support for negative offsets has been added.

    Examples

    Example #1 stripos() examples

    <?php
    $findme     = 'a';
    $mystring1 = 'xyz';
    $mystring2 = 'ABC';

    $pos1 = stripos($mystring1, $findme);
    $pos2 = stripos($mystring2, $findme);

    // Nope, 'a' is certainly not in 'xyz'
    if ($pos1 === false) {
    echo     "The string '$findme' was not found in the string '$mystring1'";
    }

    // Note our use of ===. Simply == would not work as expected
    // because the position of 'a' is the 0th (first) character.
    if ($pos2 !== false) {
    echo     "We found '$findme' in '$mystring2' at position $pos2";
    }
    ?>

    Notes

    Note: This function is binary-safe.

    See Also

    • mb_stripos() - Finds position of first occurrence of a string within another, case insensitive
    • str_contains() - Determine if a string contains a given substring
    • str_ends_with() - Checks if a string ends with a given substring
    • str_starts_with() - Checks if a string starts with a given substring
    • strpos() - Find the position of the first occurrence of a 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
    • stristr() - Case-insensitive strstr
    • substr() - Return part of a string
    • str_ireplace() - Case-insensitive version of str_replace

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    User Contributed Notes 5 notes

    up
    41
    emperorshishire at gmail dot com
    15 years ago
    I found myself needing to find the first position of multiple needles in one haystack. So I wrote this little function:

    <?php
    function multineedle_stripos($haystack, $needles, $offset=0) {
    foreach(    $needles as $needle) {
    $found[$needle] = stripos($haystack, $needle, $offset);
    }
    return     $found;
    }

    // It works as such:
    $haystack = "The quick brown fox jumps over the lazy dog.";
    $needle = array("fox", "dog", ".", "duck")
    var_dump(multineedle_stripos($haystack, $needle));
    /* Output:
    array(3) {
    ["fox"]=>
    int(16)
    ["dog"]=>
    int(40)
    ["."]=>
    int(43)
    ["duck"]=>
    bool(false)
    }
    */
    ?>
    up
    8
    sorrynorealemail at example dot com
    6 years ago
    Unlike strpos() it seems that stripos() does NOT issue a WARNING if the needle is an empty string ''.
    up
    5
    spam at kleppinger dot com
    9 years ago
    Regarding the function by spam at wikicms dot org

    It is very bad practice to use the same function name as an existing php function but have a different output format. Someone maintaining the code in the future is likely to be very confused by this. It will also be hard to eradicate from a codebase because the naming is identical so each use of stripos() would have to be analyzed to see how it is expecting the output format (bool or number/bool).

    Calling it string_found() or something like that would make a lot more sense for long-term use.
    up
    3
    emanuel dot karlsson at rolfsbuss dot se
    6 years ago
    Finding numbers in strings requires you to cast the number to string first.

    strpos("123", 2) !== strpos("123", "2")
    up
    3
    Ian Macdonald
    9 years ago
    Regarding the === note, it might be worth clarifying that the correct tests for a binary found/not found condition are !==false to detect found, and ===false to detect not found.
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