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in_array

(PHP 4, PHP 5, PHP 7)

in_arrayChecks if a value exists in an array

Description

in_array ( mixed $needle , array $haystack [, bool $strict = false ] ) : bool

Searches for needle in haystack using loose comparison unless strict is set.

Parameters

needle

The searched value.

Note:

If needle is a string, the comparison is done in a case-sensitive manner.

haystack

The array.

strict

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.

Return Values

Returns true if needle is found in the array, false otherwise.

Examples

Example #1 in_array() example

<?php
$os = array("Mac", "NT", "Irix", "Linux");
if (in_array("Irix", $os)) {
    echo "Got Irix";
}
if (in_array("mac", $os)) {
    echo "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";
}
?>

The above example will output:

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";
}
?>

The above example will output:

  'ph' was found
  'o' was found

See Also

  • array_search() - Searches the array for a given value and returns the first corresponding key if successful
  • isset() - Determine if a variable is declared and is different than null
  • array_key_exists() - Checks if the given key or index exists in the array

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Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.in-array.php