While JavaScript is easy for beginners, learn how type coercion in JavaScript can be difficult and how to work around it.

Type coercion, type conversion, typecasting, and type juggling: all different names that refer to the process of converting one data type into another. This process is present in almost every programming language and is an important concept in computer science.

While JavaScript is known as one of the easiest programming languages for beginners, it can also become frustrating when developers expect JavaScript to do one thing and it returns another.

And while the ECMAScript Language Specification standard is available to developers to help guide them through these issues, not reading and understanding the specification standard can cause more frustration when dealing with type coercion in JavaScript.

Type coercion in JavaScript is an example of how the language can produce unexpected results when we don’t know exactly how it works. Everyone who has touched even a little bit of code in JavaScript can relate that type coercion can be tricky.

While the code examples we cover in this article may seem like bugs that a version update could fix, the reason we review why type coercion acts the way it does is because many legacy products and code depend on older versions of JavaScript.

This means that creating changes to the language can break legacy products and code, and we must instead learn how to navigate the quirks of type coercion.

In this post, we’ll cover what types are in JavaScript and how to use type coercion, setting us up for programming success.

Types in JavaScript

We can refer to JavaScript as an untyped language, which means that it has no static types. However, the prominent myth that JavaScript doesn’t have types is false.

JavaScript has seven primitive types:

• string
• number
• Boolean
• undefined
• null
• Symbol
• BigInt

Variables in JavaScript don’t have types, however. Whenever we use the typeof operator to return a variable type, we return the variable’s value type.

Now that we have cleared up a few misconceptions about JavaScript and types, we can learn more about type coercion and how it works in JavaScript.

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