How to display the value of an array by index and field name?

Question

PHP

Help solve the problem, please.
Problem condition:
An array is given:

$arrEmployees = [
      1 => [
        'name' => 'user1',
        'surname' => 'surname1',
        'salary' => 1000,
      ],
      2 => [
        'name' => 'user2',
        'surname' => 'surname2',
        'salary' => 2000,
      ],
      3 => [
        'name' => 'user3',
        'surname' => 'surname3',
        'salary' => 3000,
      ],
      4 => [
        'name' => 'user4',
        'surname' => 'surname4',
        'salary' => 4000,
      ],
      5 => [
        'name' => 'user5',
        'surname' => 'surname5',
        'salary' => 5000,
      ],
    ];

It is necessary to build a function with two parameters - $num (user number by key - from 1 to 5) and $str (one of the names of the array fields - name, surname or salary. The function should display the value of the array field based on the two input parameters.

Answer 1

and what's the problem? https://ideone.com/Un1FZO
I'll leave the beautification and error checking to you.