Currently, a lot of my watcher code looks like this:

```
watch: {
  // whenever question changes, this function will run
  question: function (newQuestion, oldQuestion) {
    if (newQuestion != oldQuestion) {
       // do something
    }
  }
},

```

My question is if I need `newQuestion != oldQuestion` or does Vue not trigger the watcher if `newQuestion = oldQuestion`. If the latter is true, then what kind of inequalities does Vue check for? Just `=` or deep equality (e.g. all checking if elements of array are same even if arrays aren't the same) as well?