PHP 手冊
前一頁 |  | 下一頁

# in_array

(PHP 4 , PHP 5)

in_array -- Checks 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.

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

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

範例 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

範例 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

範例 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(), array_key_exists(), and isset().

前一頁 | 內容 | 下一頁
extract | 上一層 | key