- Using typeof
You must use typeof only if you need to check whether a variable is defined or not. Otherwise, you’ll experience dreadfully inconsistent behavior.
- Using “==”rather than “===”
For beginners, this is one of the usual mistakes. The main difference between these symbols is that “==” converts the type while “===” won’t. Generally, you must use “===” or the Strict Equality Operator as it enables more a predictable behavior. Also, it minimizes hard-to-track bugs.
- Not maximizing anonymous wrappers
Using anonymous wrappers will help here. Anonymous functions generally are viewed as values, so they need evaluation before they could be callable. This keeps name clashes at bay and organizes your code better.
- Using “this” incorrectly in a class
- Mistakenly Iterating Through Keys of an Object
Many beginners also get slip-ups with this aspect. There are various means to iterate with the specific properties of a particular object. You may use Object.entries, Object.keys, or a for in a loop.
- Deleting Semi-Colons
Omitting semi-colons can ruin your code as well as lead to unknown errors. To do away from this, use a linter in order to ensure that semi-colons aren’t forgotten. Also, put the braces right on the same line of the corresponding statement to avoid unwanted behavior.
- Memory Leaks
It refers to the memory that’s no longer used by the app. Various languages have various memory management systems. It’s a mistake not to recognize that memory management can actually be handled on the developers’ end. As you write the code, you as the developer can inform the program whether the value is free or occupied.