Introduction to the v for command in the vue component and analysis of alarm problems when using v-for-JS Tutorial-php.cn

Introduction to the v for command in the vue component and analysis of alarm problems when using v-for

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Release： 2017-12-22 10:33:30

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We know that the basic use of v-for is v-for="item in list" or v-for="item of list" for traversal. This article mainly introduces how to solve the alarm problem when using v-for in the vue component. In the article, I introduce the v for command to everyone. Friends who need it can refer to it. I hope it can help everyone.

When running the v-for code snippet in the project,

<flexbox v-if="roleShow" style="padding:15px; box-sizing: border-box;"> 
  <flexbox-item v-for="role in roles " > 
    <x-button mini :type="role.type" style="padding: 0 14px" @click.native="btnClick(role.action)">{{role.value}}</x-button> 
  </flexbox-item> 
</flexbox> 
<flexbox v-if="roleShow" style="padding:15px; box-sizing: border-box;">
  <flexbox-item v-for="role in roles " >
    <x-button mini :type="role.type" style="padding: 0 14px" @click.native="btnClick(role.action)">{{role.value}}</x-button>
  </flexbox-item>
</flexbox>出现告警：component lists rendered with v-for should have explicit keys. See https://vuejs.org/guide/list.html#key for more info.

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Solution:

Bind the key value in the code, which can be solved, such as:

<flexbox v-if="roleShow" style="padding:15px; box-sizing: border-box;"> 
  <flexbox-item v-for="(role,index) in roles " :key="index" > 
    <x-button mini :type="role.type" style="padding: 0 14px" @click.native="btnClick(role.action)">{{role.value}}</x-button> 
  </flexbox-item> 
</flexbox>

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PS: Vue2 study notes :v-for command

1.Use

<!DOCTYPE html>
<html>
<head>
  <title></title>
  <meta charset="utf-8">
  <script src="http://unpkg.com/vue/dist/vue.js"></script>
  <script type="text/javascript">
    window.onload = function(){
      var vm = new Vue({
        el:&#39;#box&#39;,
        data:{
          arr:[&#39;1&#39;,&#39;2&#39;,&#39;3&#39;],
          json:{a:&#39;a&#39;,b:&#39;b&#39;}
        }
      });
    }
  </script>
</head>
<body>
  <p id="box">
    <p>循环数组</p>
    <ul>
      <li v-for="a in arr">
      {{a}}
      </li>
    </ul>
    <hr>
    <p>循环出数组索引</p>
    <ul>
      <li v-for="(v,k) in arr">
      {{v}}==>{{k}}
　　　　　　　</li>
    </ul>
    <p>循环json</p>
    <ul>
      <li v-for="item in json">{{item}}</li>
    </ul>
    <p>循环json的键</p>
    <ul>
      <li v-for="(k,v) in json">
      {{k}}==>{{v}}
      </li>
    </ul>
  </p>
</body>
</html>

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Result:

Summary

Regarding solving the alarm problem when using v-for in the vue component, I hope it will be helpful to everyone It's helpful. If you have any questions, please leave me a message and I will reply to you in time!

Related recommendations:

Vue.js Common Instructions - Tutorial on Looping the v-for Instruction

vue.js Instruction v-for Usage and index acquisition

Vue.js common instructions summary (v-if, v-for, etc.)

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