Check if a Key Exists in an Object

JavaScript Program to Check if a Key Exists in an Object

In this example, you will learn to write a JavaScript program that checks if a key exists in an object.

To understand this example, you should have the knowledge of the following JavaScript programming topics:

JavaScript Objects

JavaScript Object hasOwnProperty()

Example 1: Check if Key Exists in Object Using in Operator

In the above program, the in operator is used to check if a key exists in an object.

The in operator returns true if the specified key is in the object, otherwise it returns false.

Example 2: Check if Key Exists in Object Using hasOwnProperty()

In the above program, the hasOwnProperty() method is used to check if a key exists in an object.

The hasOwnProperty() method returns true if the specified key is in the object, otherwise it returns false.