If you write JavaScript, you have probably used higher-order functions and not even noticed. If you have ever replaced a for loop with an array method, you’ve used higher-order functions.

Here are some fundamental concepts in JavaScript: Variables: Data storage variables or structures in which different values are stored. In JavaScript there are three ways to declare a variable using ...

Ordinarily with JavaScript, you can change pretty much any variable you want. Any variable you declare can be reassigned to any other value, unless you use the const keyword.