Variables in JavaScript are commonly declared by using a var keyword, followed by a variable name, assignment operator (equals sign =), and a corresponding value.

1var number = 21;
2console.log(number); // prints 21

This will display the value 21, and this is verified by printing the variable value on the console.

In ES6, the variable declaration keywords let and const were introduced. We covered these keywords briefly in the last lesson. var has some weaknesses in terms of scope, and let and const are now preferred. For a deep dive of the difference between the three, check out this article.

1let number = 21;
2console.log(number); // prints 21

Let's test your variable knowledge with some short questions!