Difference between null and undefined

In JavaScript, null and undefined are primitive data types used to indicate the absence of a value, but they have different meanings and use cases.

undefined — means something is not defined. For example, a variable is created but nothing is assigned to it:

bash

let x; // x is undefined because we didn't assign a value
console.log(x); // undefined

null — means you explicitly stated that there's nothing here. For example:

bash

let y = null; // y is "nothing" because we decided so
console.log(y); // null

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