text: const a = [ 1, 2, 3 ];
  const b = [ 4, 5, 6 ];
  const c = [ ...a, ...b, 7, 8, 9 ];
  
  console.log(c);  // -> [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ]
  
  const d = [ a, b, 7, 8, 9 ];
  console.log(d); // -> [ [ 1, 2, 3 ], [ 4, 5, 6 ], 7, 8, 9 ]
  