Cannot read property 'name' of null error - node.js

Question

I'm still a baby on web development. I am getting the following error, can
anyone help me?
Schema:
var campgroundSchema = new mongoose.Schema({
name: String,
image: String,
description: String,
_id: String
});
var Campground = mongoose.model("Campground", campgroundSchema);
app.get("/campgrounds/:id",function(req , res){
Campground.findById(req.params.id, function(err, foundCampgrounds){
if(err){
console.log(err);
}else{
res.render("show", {campground: foundCampgrounds});
}
});
});
This is the index.ejs template:
<div class="row text-center" style="display:flex; flex-wrap:wrap">
<% campgrounds.forEach(function(campground){ %>
<div class="col-md-3 col-sm-6">
<div class="thumbnail">
<img src="<%= campground.image %>">
<div class="caption">
<h4> <%= campground.name %> </h4>
</div>
<p><a href="/campgrounds/ <%= campground._id %>"
class="btn btn-primary">More Info</a>
</p>
</div>
</div>
<% }) %>
</div>
show.ejs:
<%- include('partials/header')%>
<h1>this is a show template</h1>
<p><%= campground.name %></p>
<%- include('partials/footer')%>
TypeError:
Cannot read property 'name' of null

Answer 1

You should check if campground is defined at all - you can either do that in your nodejs-controller or in your template. Here's an example for ejs:
<%- include('partials/header')%>
<% if (campground) { %>
<h1>this is a show template</h1>
<p><%= campground.name %></p>
<% } else { %>
<h1>No camground data was found</h1>
<% } %>
<%- include('partials/footer')%>

Answer 2

On the index.ejs. Use a span to retrieve the _id from the
DB, as follows
<span> <%= campground._id %> </span>
Why? Because _id is a unique object and is auto-generated. No need to even
include it on the Schema unless you want to create it yourself on which case
you'll then amend the controller with a variable. I struggled with this but now
okay.