How to use Vue computed-JS Tutorial-php.cn

How to use Vue computed

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Release： 2018-06-14 10:07:24

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This time I will show you how to use Vue computed, such as what are the precautions for using Vue computed. The following is a practical case, let's take a look.

Computed in Vue can be used to simply splice the data that needs to be displayed

computed and methods

The task of splicing and displaying data is also It can be done with methods, but when the data on the page changes, the methods in methods will be called again (causing unnecessary performance consumption), and the methods in methods will only be called when the data related to itself changes

A simple example

computed is only called during initialization

methods will It is called when the data changes, even if the changed data has nothing to do with itself

Test source code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>computed的使用</title>
  <script src="https://cdn.bootcss.com/vue/2.5.16/vue.js"></script>
</head>
<body>
  <p id="root">
  </p>
  <script>
    var vm = new Vue({
      el: "#root",
      data: {
        name: "zhaozhao",
        age: 13,
        hobby: 'Python',
        nameAgeStyle: {
          fontSize: "20px",
          color: "#0c8ac5"
        }
      },
      template: `<p>
        <p v-bind:style="nameAgeStyle">computed方式渲染: {{nameAndAge}}</p>
        <p v-bind:style="nameAgeStyle">methods 方式渲染: {{getNameAndAge()}}</p>
        <br>
        <input type="text" v-model="hobby">
        <p>爱好: {{hobby}}</p>
        <p>{{noUse()}}</p>
        </p>`,
      computed: {
        nameAndAge: {
          get(){
          console.log('调用computed');
          return `${this.name} ==> ${this.age}`;
          }
        }
      },
      methods: {
        getNameAndAge() {
          console.log('调用methods');
          return `${this.name} ==> ${this.age}`;
        },
        noUse(){
          console.log("=methods==nouse==");
        }
      }
    })
  </script>
</body>
</html>

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I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related topics on the PHP Chinese website article!