cannot call method foreach of undefined问题

本文详细介绍了在Node.js博客实现留言功能时遇到的cannot call method forEach of undefined错误的原因和解决方案。通过分析问题所在,我们发现是由于comment[]数组为空导致的错误。解决方法是在comment.ejs页面中暂时去除显示评论的代码,添加一条评论后再重新启用显示代码,从而避免了错误并使博客功能正常运行。

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在node.js的教程,一个简单的博客中。当我们进行到第六章“

第6章 实现留言功能

时,会遇到一个问题


cannot call method foreach of undefined问题


原因很简单,是由于comment[]数组是空的,所以当使用foreach循环时,就会报错。


解决的方法在于comment.ejs页面,去掉显示评论的那一段代码,然后就可以正常运行,添加一次评论后再加上显示代码,即可正常运行。


<% post.comments.forEach(function (comment, index) { %>
  <p><a href="<%= comment.website %>"><%= comment.name %></a>
  <span class="info"> 回复于 <%= comment.time %></span></p>
  <p><%- comment.content %></p>
<% }) %>

我用了方案1,现在报错了:12:42:58.678 跳转登录页成功 at pages/index/index.vue:16 12:43:07.960 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:07.960 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:07.960 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:07.960 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:07.960 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.012 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.012 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.012 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.012 [JS Framework] Failed to execute the callback function: TypeError: Cannot read property 'left' of null 12:43:08.012 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.012 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.012 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.013 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.013 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.013 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.013 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.013 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.013 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7 12:43:08.013 reportJSException >>>> exception function:__WEEX_CALL_JAVASCRIPT__, exception:JavaScript execute error!Uncaught TypeError: Cannot read property 'left' of null at (app-service.js:1701:40) 12:43:08.013 Uncaught TypeError: Cannot read properties of undefined (reading '$') at uni-app-view.umd.js:7
最新发布
07-24
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