Pass by reference variable warning in end()

Question

How do you remove this warning?

Strict Standards: Only variables should be passed by reference in

I have code that gets unique values from a multidimensional array and then gets the last index.

$catchColors[]= array();

for ($i = 0; $i < $totalRows; $i++) {
    $catchColors[$i] = $postData[$i]['ColorID'];
}

$result = array_unique($catchColors);
print_r($result);

print end(array_keys($result));

it still returns the value, but how do I remove the warning?

Answer 1

That's because the parameter for the function end will be passed by reference. Thus, it can't be a return of another function, it should be, as the notice says, an actual variable.

So, a solution is to create a temporary variable to hold the array of the keys, and then execute end in that array.

$keys = array_keys($result);
print end($keys);