PHP Array Search Return Multiple Keys

Question

I'm trying to search an array and return multiple keys

<?php
$a=array("a"=>"1","b"=>"2","c"=>"2");
echo array_search("2",$a);
?>

With the code above it only returns b, how can I get I to return b and c?

Answer 1

As it says in the manual for array_search:

To return the keys for all matching values, use array_keys() with the optional search_value parameter instead.

---

Example:

$a=array("a"=>"1","b"=>"2","c"=>"2");
print_r(array_keys($a, "2"));

Result:

Array
(
    [0] => b
    [1] => c
)

Answer 2

I am adding this in case someone finds it helpful. If you're doing with multi-dimensional arrays. Suppose you have this

        $a = array(['user_id' => 2, 'email_id' => 1], ['user_id' => 2, 'email_id' => 2, ['user_id' => 3, 'email_id' => 1]]);

You want to find email_id of user_id 2. You can do this

        print_r(array_keys(array_column($a, 'user_id'), 2));

This will return [0,1]

Hope this helps.