4 ms·

Just always use !==. != will automatically cast and !== won't, therefore "1" != 1 is false and "1" !== 1 is true.

• hellcow 3y ago
  Unless you’re testing if something is null or undefined, in which case a single “x != null” handles it.
  • fzzzy 3y ago
    Sure. I usually just use !x for that.
    • SamBam 3y ago
      That doesn't test if it's null or undefined, that just tests if it's not falsy. x = 0; !x → true y = ""; !y → true z = null; !z → true
• deleted 3y ago
  [deleted]