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# in_array

(PHP 4 )

in_array -- Return `TRUE` if a value exists in an array

## Description

bool in_array ( mixed needle, array haystack [, bool strict])

Searches `haystack` for `needle` and returns `TRUE` if it is found in the array, `FALSE` otherwise.

If the third parameter `strict` is set to `TRUE` then the in_array() function will also check the types of the `needle` in the `haystack`.

> Note: If `needle` is a string, the comparison is done in a case-sensitive manner.

> Note: In PHP versions before 4.2.0 `needle` was not allowed to be an array.

Example 1. in_array() example
    $os = array ("Mac", "NT", "Irix", "Linux");
    if (in_array ("Irix", $os)) {
        print "Got Irix";
    }
    if (in_array ("mac", $os)) {
        print "Got mac";
    }
The second condition fails because in_array() is case-sensitive, so the program above will display:
    Got Irix

Example 2. in_array() with strict example
    <?php
    $a = array('1.10', 12.4, 1.13);

    if (in_array('12.4', $a, TRUE))
        echo "'12.4' found with strict check\n";
    if (in_array(1.13, $a, TRUE))
        echo "1.13 found with strict check\n";
    ?>
This will display:
    1.13 found with strict check

Example 3. in_array() with an array as needle
    <?php
    $a = array(array('p', 'h'), array('p', 'r'), 'o');

    if (in_array(array ('p', 'h'), $a))
        echo "'ph' was found\n";
    if (in_array(array ('f', 'i'), $a))
        echo "'fi' was found\n";
    if (in_array('o', $a))
        echo "'o' was found\n";
    ?>

    // This will output:

    'ph' was found
    'o' was found

See also array_search().

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