Strict Mode

When doing coding exercises in plain vanilla js, I should use strict mode to help me write cleaner code.

impossible to accidentally declare global variables with typos
makes silent errors throw errors

Use at top declaration:

"use strict"

Use for function

function strict() {
  'use strict';
  function nested() { return 'And so am I!'; }
  return "Hi!  I'm a strict mode function!  " + nested();
}
function notStrict() { return "I'm not strict."; }

Use for module

function strict() {
    // because this is a module, I'm strict by default
}
export default strict;

Source -> Strict Mode on MDN docs