Cannot read property 'substring' of undefined in ejs

Question

When I try to add new blog posts to my website I am continuously getting this error:

TypeError: C:\Users\shruti\Desktop\ejs-challenge\views\home.ejs:15 13|
14|       <p>

15|         <%= post.content.substr(0, 100) %>

16|         <a href="/posts/<%=post._id%>">Read More</a>

17|       </p>

18|       <% })%>
Cannot read property 'substr' of undefined at eval (eval at compile (C:\Users\shruti\Desktop\ejs-challenge\node_modules\ejs\lib\ejs.js:618:12), :22:39) at Array.forEach () at eval (eval at compile (C:\Users\shruti\Desktop\ejs-challenge\node_modules\ejs\lib\ejs.js:618:12), :16:14) at returnedFn (C:\Users\shruti\Desktop\ejs-challenge\node_modules\ejs\lib\ejs.js:653:17) at tryHandleCache (C:\Users\shruti\Desktop\ejs-challenge\node_modules\ejs\lib\ejs.js:251:36) at View.exports.renderFile [as engine] (C:\Users\shruti\Desktop\ejs-challenge\node_modules\ejs\lib\ejs.js:482:10) at View.render (C:\Users\shruti\Desktop\ejs-challenge\node_modules\express\lib\view.js:135:8) at tryRender (C:\Users\shruti\Desktop\ejs-challenge\node_modules\express\lib\application.js:640:10) at Function.render (C:\Users\shruti\Desktop\ejs-challenge\node_modules\express\lib\application.js:592:3) at ServerResponse.render (C:\Users\shruti\Desktop\ejs-challenge\node_modules\express\lib\response.js:1008:7) at C:\Users\shruti\Desktop\ejs-challenge\app.js:35:9 at C:\Users\shruti\Desktop\ejs-challenge\node_modules\mongoose\lib\model.js:4846:16 at C:\Users\shruti\Desktop\ejs-challenge\node_modules\mongoose\lib\model.js:4846:16 at C:\Users\shruti\Desktop\ejs-challenge\node_modules\mongoose\lib\helpers\promiseOrCallback.js:24:16 at C:\Users\shruti\Desktop\ejs-challenge\node_modules\mongoose\lib\model.js:4869:21 at C:\Users\shruti\Desktop\ejs-challenge\node_modules\mongoose\lib\query.js:4397:11

home.ejs:

<%- include("partials/header") -%>

    <h1>HOME</h1>
    <p> <%= startingContent %> </p>

    <% console.log(posts); %>

    <div class="">
      <% posts.forEach(function(post){ %>
      <h1><%= post.title%></h1>

      <p>
        <%= post.content.substr(0, 100) %>
        <a href="/posts/<%=post._id%>">Read More</a>
      </p>
      <% })%>


        <form  action="/compose">
           <button class="btn btn-primary" type="compose" name="button">COMPOSE</button>
        </form>

    </div>


    <%- include("partials/footer") -%>

Does this answer your question? How to set character limits in content in ejs template — dawsnap

Zsolt Meszaros Zsolt Meszaros · Accepted Answer · 2020-11-30T12:01:28

The error message says that it "Cannot read property 'substr' of undefined", which means post.content is undefined inside your posts.forEach() loop. Try to log post and check its content.

Cannot read property 'substring' of undefined in ejs

1 Answers