Error: Unexpected end of input

Uncaught SyntaxError: Unexpected end of input.

I know this very error has kept me up at night sometimes. Don’t sweat it! This article will talk about ways to help you debug your code so you can conquer this error and move on with your project.

What does it mean?

More likely than not, it means you have mismatching brackets or quotes somewhere in your code. Ultimately, it is because the V8 engine is parsing your code in a certain way and is looking for a particular character.

If the error gives you a line and char number, that’s a good place to start hunting. If not at that point, backtrack in your code until you find it.

How can I find it? 

There are a couple of things you can do to help find syntax bugs in your code: 

1. Make sure everything is indented correctly. An extension like Prettier or Beautify can help in this regard. However, if you have an error in your syntax, the extension won’t run or will work incorrectly. Indentation makes your code more readable, even if it’s not necessarily required to run in a language like JavaScript.
2. Use the dropdown arrows on the left hand side of your editor to hide elements. If your elements have matching opening and closing brackets, the block will collapse. Here’s an example:

Without clicking dropdowns:

With clicking dropdowns:

This will take attention away from the elements you don’t need to concentrate on, and bring attention to places that might not have matching brackets. If you are not able to collapse it properly, there is more than likely a syntax error in that block of code.

The more you perform code review or the more you encounter this error, the faster you will get at spotting these types of errors! Good luck debugging!