PHP if in_array() how to get the key as well?

Question

Struggling with a tiny problem.

I have an array:

Array (     [0] =>      [6] => 6     [3] => 5     [2] => 7 ) 

I am checking if a set value is in the array.

if(in_array(5, $array)) { //do something } else { // do something else } 

The thing is, when it find the value 5 in array, I really need the key to work with in my "do something".

In this case I need to set:

$key = 3; 

(key from the found value in_array).

Any suggestions?

Answer 1

array_search() is what you are looking for.

if (false !== $key = array_search(5, $array)) {     //do something } else {     // do something else } 

Answer 2

If you only need the key of the first match, use array_search():

$key = array_search(5, $array); if ($key !== false) {     // Found... } 

If you need the keys of all entries that match a specific value, use array_keys():

$keys = array_keys($array, 5); if (count($keys) > 0) {     // At least one match... }