title: How do I find out which item in a watched array is changed in VueJS?
body: <p>Let's say I have an array declared in the data section</p>
  
  <pre><code>data() {
     return {
        myData : [{foo:2, bar:3},{foo:4,bar:5}]
     }
  }
  </code></pre>
  
  <p>When I change the <code>bar</code> property of the <code>second</code> element, I want to know that the second element was changed.</p>
  
  <p>What would my watch function look like?</p>
  
  <pre><code>watch : {
    myData : {
       deep : true,
       handler(oldVal, newVal) {
        console.log("New val is the entire myData[] array which is not what I want", newVal);
        // I also want to know what index of the array the changed value belonged to.
  
       }
    }
  }
  </code></pre>