JS: null

What is null

• null is a literal expression, e.g. you can write let x = null;
• null is one of the type of JavaScript values, and it is the only value of that type. [see Value Types]

typeof null

typeof null return "object". (this is a historical bug. typeof null should return "null" )

console.assert(typeof null === "object");

Why typeof null return object

• In JavaScript, why typeof null return object?

What is the Use of null

There are 2 major uses of null.

• you can set a object's prototype (parent) to null, to make it having no prototype. [see Get Set Prototype] Or, use Object.create with null to create a object with no parent.
• You can set a variable to null as default initial value. (unassigned variable has default value of undefined. [see undefined]).