Q
How can you check if the age property exists in the person object?

Answer & Solution

Answer: Option D
Solution:
person.hasOwnProperty('age') checks if age is a direct property of person.
Related Questions on Average

What will console.log(newCar.make); output if class Car { constructor(make) { this.make = make; }} var newCar = new Car('Honda');?

A). Honda

B). Car

C). Undefined

D). Error

What will console.log(car.make); output if var car = {make: 'Toyota', model: 'Corolla'};?

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A). person.gender = 'male';

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How do you access the value of the name property in the object var person = {name: 'John', age: 30};?

A). person['name']

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How do you define a constructor function for creating Car objects?

A). function Car(make, model) { this.make = make; this.model = model; }

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How do you call a method from a parent class in a subclass in JavaScript ES6?

A). super.methodName()

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What is the output of console.log(person.greet()); if var person = {greet: function() {return 'Hello';}};?

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A). class SubClass extends SuperClass {}

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What does Object.keys(person) return if var person = {name: 'John', age: 30};?

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