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

How do you define a class in JavaScript ES6?

A). class ClassName { constructor() {} }

B). function ClassName() { constructor() {} }

C). class ClassName() { constructor {} }

D). function class ClassName { constructor() {} }

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

A). person['name']

B). person.name

C). person->name

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A). this.methodName = function() {}

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

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

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

How do you add a new property gender with value male to the person object?

A). person.gender = 'male';

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How can you delete the age property from the person object?

A). delete person.age;

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C). person.age = null;

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What is the correct way to create an object in JavaScript?

A). var obj = {};

B). var obj = [];

C). var obj = ();

D). var obj = {};

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

A). super.methodName()

B). this.methodName()

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D). base.methodName()

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A). methodName() {}

B). this.methodName = function() {}

C). function methodName() {}

D). methodName: function() {}

How do you define a method named greet in an object var person = {};?

A). person.greet = function() {};

B). person.greet: function() {};

C). person.greet = () {};

D). person.greet = function {};