Use 'this' in Vue template?

Question

I'm mixed in my head : I don't know why I see somewhere that we can use this in Vue.js template. Now I don't know which I must use.

I test some case here :

new Vue({
  el: "#app",
  data: function() {
  	return {
    	myVar: 'test'
    }
  },
  methods: {
    returnText: function() {
    	console.log('methods returnText !');
      return 'return text from methods !';
    }
  },
  computed: {
    computedProp: function() {
    	return 'computed !';
    }
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.2.5/vue.js"></script>

<div id="app">

  {{ this.myVar }}<br><!-- this works -->
  {{ myVar }}<br><!-- this works -->
  <button @click="myVar = 'test without this !'" type="button">
          Change text</button><!-- this works --><br>

  <button @click="this.myVar = 'test with this !'" type="button">
          Change text (not working because of 'this')</button><!-- this NOT works -->
  <br><br>
  
  {{ computedProp }} <!-- this works -->
  <br>
  {{ this.computedProp }} <!-- this works -->
  
  <br><br>
  {{ returnText() }} <!-- this works -->
  <br>
  {{ this.returnText() }} <!-- this works -->
</div>

What is the recommendation ?

Answer 1

In template you don't need to use this, you use this in functions like mounted(), created(), or in methods, etc. All lifecycle hooks are called in this context pointing to the invoking Vue instance.

https://vuejs.org/v2/guide/instance.html