Hướng dẫn check value array php

(PHP 4, PHP 5, PHP 7, PHP 8)

Nội dung chính Show

Description
Return Values

in_array — Checks if a value exists in an array

Description

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

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.

Note:
Prior to PHP 8.0.0, a string needle will match an array value of 0 in non-strict mode, and vice versa. That may lead to undesireable results. Similar edge cases exist for other types, as well. If not absolutely certain of the types of values involved, always use the strict flag to avoid unexpected behavior.

Return Values

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

Examples

Example #1 in_array() example

$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:

Example #2 in_array() with strict example

$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

$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

in_array(null, $array); // true
in_array(false, $array); // true
in_array(765, $array); // true
in_array(763, $array); // true
in_array('egg', $array); // true
in_array('hhh', $array); // true
in_array(array(), $array); // true// Strict checkingin_array(null, $array, true); // true
in_array(false, $array, true); // true
in_array(765, $array, true); // true
in_array(763, $array, true); // false
in_array('egg', $array, true); // false
in_array('hhh', $array, true); // false
in_array(array(), $array, true); // false?>

rhill at xenu-directory dot net ¶

13 years ago

I found out that in_array will *not* find an associative array within a haystack of associative arrays in strict mode if the keys were not generated in the *same order*:

$needle

= array(
    'fruit'=>'banana', 'vegetable'=>'carrot'
    );$haystack = array(
    array('vegetable'=>'carrot', 'fruit'=>'banana'),
    array('fruit'=>'apple', 'vegetable'=>'celery')
    );echo in_array($needle, $haystack, true) ? 'true' : 'false';
// Output is 'false'echo in_array($needle, $haystack) ? 'true' : 'false';
// Output is 'true'?>

I had wrongly assumed the order of the items in an associative array were irrelevant, regardless of whether 'strict' is TRUE or FALSE: The order is irrelevant *only* if not in strict mode.

thomas dot sahlin at gmail dot com ¶

12 years ago

If you're creating an array yourself and then using in_array to search it, consider setting the keys of the array and using isset instead since it's much faster.

$slow

= array('apple', 'banana', 'orange');if (in_array('banana', $slow))
    print('Found it!');$fast = array('apple' => 'apple', 'banana' => 'banana', 'orange' => 'orange');if (isset($fast['banana']))
    print('Found it!');?>

Hướng dẫn check value array php

Description

Parameters

Return Values

Examples

See Also

Bài Viết Liên Quan

Quảng Cáo

Có thể bạn quan tâm

Toplist được quan tâm

Quảng cáo

Xem Nhiều

Quảng cáo

Chúng tôi

Điều khoản

Trợ giúp

Mạng xã hội