Get the first level key of the row with a qualifying column value in a 2d array

Have some problems with checking if a value exists in a 2d array. I have a field in my database table where I save my data in JSON. I parse it this way:

$this_will_be_saved = json_encode($array);

Now I need to add some data to the array, but I need to check if the array already has that item:

$this_will_be_saved = json_decode($this_will_be_saved, true);

Decoded array structure:

array(5) {
  [0]=>
  array(2) {
    ["rating"]=>
    int(9)
    ["userid"]=>
    int(1)
  }
  [1]=>
  array(2) {
    ["rating"]=>
    int(9)
    ["userid"]=>
    int(1)
  }
  [2]=>
  array(2) {
    ["rating"]=>
    int(9)
    ["userid"]=>
    int(1)
  }
  [3]=>
  array(2) {
    ["rating"]=>
    int(1)
    ["userid"]=>
    int(1)
  }
  [4]=>
  array(2) {
    ["rating"]=>
    int(7)
    ["userid"]=>
    int(1)
  }
}

I try check if new added value exist in array but array_search not working :/

$key = array_search($userid, array_column($this_will_be_saved, 'userid'));
if ( $key ) {
    // found
} else {
    // not found
}

It's never finding anything, even if the user id is already in a row.

array_search() returns the first corresponding key, if it finds the value in the array.

The first key of your array is 0 that is the same as false (returned by array_search() when it cannot find the value in the array) when evaluated in boolean context.
An if expression is such a context (if ($key) in your code).

Accordingly, if $userid is 1, array_search() returns 0 and the if statement correctly takes the else branch.

Use in_array() to check if a value exists in an array:

$found = in_array($userid, array_column($this_will_be_saved, 'userid'));
if ($found) {
    // found
} else {
    // not found
}