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Discover how to resolve the `undefined method 'each' for nil:NilClass` error in Rails 5.0.7.2 caused by a simple typo.
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Troubleshooting the undefined method 'each' for nil:NilClass Error in Rails 5.0.7.2

As you dive into the world of Rails development, you may encounter various errors along the way. One such common issue is the undefined method 'each' for nil:NilClass error, which can be bewildering, especially for newbies. In this guide, we will explore what this error means, why it occurs, and how to fix it. Our focus will be on a specific case where the error arises in a Rails application using version 5.0.7.2.

The Problem

Imagine you are working on a Rails project where you are attempting to loop through a collection of items to display them on a webpage. However, when you try to run the code, you are greeted with a frustrating error message:

[[See Video to Reveal this Text or Code Snippet]]

This error indicates that you are attempting to invoke the each method on a variable that is currently nil. In simpler terms, your code expects to find a collection of items, but it finds nothing instead.

Example Scenario

Here’s a snippet of the relevant code you’re working with:

[[See Video to Reveal this Text or Code Snippet]]

In the controller, you have defined the instance variable as follows:

[[See Video to Reveal this Text or Code Snippet]]

Understanding the Cause of the Error

Looking closely at both snippets of code, you can spot a typo that contributes to the error. The instance variable in your view is defined as @ porfolio_items, but in your controller, it is correctly defined as @ portfolio_items. When you run @ porfolio_items.each, you are invoking the each method on a variable that does not exist because it is not initialized.

Key Points

Typographical Errors: Small inconsistencies in variable names can lead to significant issues in your application.

Nil Class Errors: Attempting to call a method on a nil object usually indicates that the expected object was either not initialized or not assigned correctly.

How to Fix the Error

To resolve the undefined method 'each' for nil:NilClass error, you simply need to correct the typo in your view template. Change @ porfolio_items to the correct variable name @ portfolio_items as shown below:

[[See Video to Reveal this Text or Code Snippet]]

By making this simple correction, your code should work as intended without any errors.

Conclusion

In conclusion, while learning Rails, it’s important to pay close attention to the details in your code, especially with variable names. A small typo can lead to frustrating bugs that can halt your development process. Always remember to check your variable declarations and usage consistently across your codebase. Happy coding!