Detailed explanation of the use of computed and methods-JS Tutorial-php.cn

Detailed explanation of the use of computed and methods

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Release： 2018-05-08 16:03:32

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This time I will bring you a detailed explanation of the use of computed and methods. What are the precautions for using computed and methods. The following is a practical case, let’s take a look.

computed and methods

The task of splicing and displaying data can also be completed using methods, but when the data on the page changes, the methods in methods will be Recall (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 be called when the data changes, even if the changed data has nothing to do with itself

testsource

<!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 articles on the php Chinese website!