in_array() and multidimensional array

Question

I use in_array() to check whether a value exists in an array like below,

$a = array(\"Mac\", \"NT\", \"Irix\", \"Linux\");
if (in_array(\"Irix\"         


        

Answer 1

Please try:

in_array("irix",array_keys($b))
in_array("Linux",array_keys($b["irix"])

Im not sure about the need, but this might work for your requirement

Answer 2

Shorter version, for multidimensional arrays created based on database result sets.

function in_array_r($array, $field, $find){
    foreach($array as $item){
        if($item[$field] == $find) return true;
    }
    return false;
}

$is_found = in_array_r($os_list, 'os_version', 'XP');

Will return if the $os_list array contains 'XP' in the os_version field.

Answer 3

For Multidimensional Children: in_array('needle', array_column($arr, 'key'))

For One Dimensional Children: in_array('needle', call_user_func_array('array_merge', $arr))

Answer 4

If you know which column to search against, you can use array_search() and array_column():

$userdb = Array
(
    (0) => Array
        (
            ('uid') => '100',
            ('name') => 'Sandra Shush',
            ('url') => 'urlof100'
        ),

    (1) => Array
        (
            ('uid') => '5465',
            ('name') => 'Stefanie Mcmohn',
            ('url') => 'urlof5465'
        ),

    (2) => Array
        (
            ('uid') => '40489',
            ('name') => 'Michael',
            ('url') => 'urlof40489'
        )
);

if(array_search('urlof5465', array_column($userdb, 'url')) !== false) {
    echo 'value is in multidim array';
}
else {
    echo 'value is not in multidim array';
}

This idea is in the comments section for array_search() on the PHP manual;

Answer 5

It works too creating first a new unidimensional Array from the original one.

$arr = array("key1"=>"value1","key2"=>"value2","key3"=>"value3");

foreach ($arr as $row)  $vector[] = $row['key1'];

in_array($needle,$vector);

Answer 6

Since PHP 5.6 there is a better and cleaner solution for the original answer :

With a multidimensional array like this :

$a = array(array("Mac", "NT"), array("Irix", "Linux"))

We can use the splat operator :

return in_array("Irix", array_merge(...$a), true)

---

If you have string keys like this :

$a = array("a" => array("Mac", "NT"), "b" => array("Irix", "Linux"))

You will have to use array_values in order to avoid the error Cannot unpack array with string keys :

return in_array("Irix", array_merge(...array_values($a)), true)