Behavior of duplicated named parameters in non-strict mode

index.js

function logParams (first, second, first) {
  console.log(first, second);
}

// first => 'Hello'
// second => 'World'
// first => '!!!'
logParams('Hello', 'World', '!!!'); // "!!!"  "World"

// first => { o: 3 }
// second => [ 1, 2, 3 ]
// first => undefined
logParams({ o: 3 }, [ 1, 2, 3 ]); // undefined  [1, 2, 3]