What Is the Difference Between Null and Undefined in Javascript?

What is the difference between null and undefined in JavaScript?

In JavaScript, both null and undefined are special values that indicate the absence of a meaningful value. However, there is a subtle difference between the two. Let’s take a look at what sets them apart.

Null

The null value is an explicit representation of nothing. It is a primitive value that can be assigned to a variable or an object property. It is also an empty object pointer, meaning it points to no object.

In JavaScript, null is an object. This is an important distinction, as it means that null is not a primitive value like undefined. It is an object with no properties or methods.

Here’s an example of how to assign a variable to null:

let myVar = null;
console.log(myVar); // Output: null

Undefined

The undefined value is an implicit representation of nothing. It is a primitive value that is automatically assigned to a variable or an object property if no value is explicitly assigned to it. It is also a non-existent object pointer, meaning it points to no object.

In JavaScript, undefined is not an object. This is an important distinction, as it means that undefined is a primitive value like null. It is not an object with any properties or methods.

Here’s an example of how to assign a variable to undefined:

let myVar;
console.log(myVar); // Output: undefined

Conclusion

In summary, the difference between null and undefined in JavaScript is that null is an explicit representation of nothing, while undefined is an implicit representation of nothing. null is an object, while undefined is a primitive value.