Avoid These Common JavaScript Mistakes

Out of the many scripting languages, JavaScript is a great option for beginners to learn. However, this does not mean that it is an easy language or that you won’t make mistakes when writing code. In this article, I will cover some of the most common JavaScript mistakes that beginners make with the intention of helping you avoid them.

Referencing code before it’s loaded

JavaScript loads and runs the code in the order in which it appears in the document. If you have a script defined in the head HTML tag that accesses the HTML element(s) on the page, an error will be thrown. The following is an example of this mistake:

To avoid making this mistake when your script relies on the HTML elements on the page, either put the JavaScript code at the end of the file, or load the JavaScript file and add an attribute (such as “defer to the script” tag). Below is an example of using the defer attribute:

Defer Attribute — This tells the browser to download only the scripts and only executes scripts after parsing the HTML file.

Using == and === Operators incorrectly

These are both comparison operators and return boolean values. The double equal operator (==), also known as a comparison operator, is used to compare two…