How to add values ​​by key?

Question

PHP

There is an array $arr, there is a loop in which I get the key and value. You need to add a key (string) and a value (int) to the array, if the key matches, the value should be added to the new value.

Answer 1

if (array_key_exists($key, $arr)
    $arr[$key] = $arr[$key] + $value
else
    $arr[$key] = $value