How to remove a property from an object in JavaScript?

In this short article, we will learn how to delete a property from a JavaScript object.

JavaScript objects are collections of different properties and types, each property has a name and a value.

Using delete operator

To delete a property from a given JavaScript object we can use the delete operator. In JavaScript, the delete operator is use to remove a property from an object.

Syntax:

delete object.property
//or
delete object['property']

Suppose we have an object person, with name, address, and occupation as properties.

const person = {
  name : 'John',
  address: 'New York',
  occupation: 'Engineer'
}

So to remove the property occupation from the person object we can use delete like this.

const person = {
  name : 'John',
  address: 'New York',
  occupation: 'Engineer'
}
delete person.occupation

console.log(person)

Output:

{ name: 'John', address: 'New York' }

As you can see, the object no longer have the occupation property.

You can also use the square bracket instead of using dot property accessor.

delete person['occupation']

However, if you don’t want to delete the property and just remove the value of it, you can just set the property value to undefined .

Setting JavaScript Object Property to undefined

Setting the property to undefined is considered to be much faster than deleting the whole property if you are operating on a large number of objects.

To set the property to undefined, you can use a dot or square bracket property accessor.

Example:

const person = {
  name : 'John',
  address: 'New York',
  occupation: 'Engineer'
}

person.occupation = undefined 
//OR
person['occupation'] = undefined

console.log(person)

Output:

{ name: 'John', address: 'New York', occupation: undefined }