Let's say you have an object called John
.
const John = {
name: "John Doe",
age: 23,
salary: 23000,
};
We can check whether the property salary
property is present in the object using the hasOwnProperty()
method available in the prototype chain of the John
object.
const John = {
name: "John Doe",
age: 23,
salary: 23000,
sayHello: () => {
console.log("Hello!");
},
};
// check if the salary is present in John
John.hasOwnProperty("salary");
- The method returns
true
if present andfalse
if not. - Available in the prototype chain of an object.
You can also check if a method is present in the object.
Now let's check if sayHello
method is present.
const John = {
name: "John Doe",
age: 23,
salary: 23000,
sayHello: () => {
console.log("Hello!");
},
};
// check if the salary is present in John
John.hasOwnProperty("salary"); // Result: true
// check if sayHello function is present in John
John.hasOwnProperty("sayHello"); // Result: true