Array Functions
PHP Manual

in_array

(PHP 4, PHP 5)

in_arrayChecks if a value exists in an array

Description

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

Searches haystack for needle 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.

Changelog

Version Description
4.2.0 needle may now be an array.

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('1.10'12.41.13);

if (
in_array('12.4'$atrue)) {
    echo 
"'12.4' found with strict check\n";
}

if (
in_array(1.13$atrue)) {
    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 Functions
PHP Manual