Q
What will the following code output? console.log(person['age']); if var person = {name: 'John'};

Answer & Solution

Answer: Option C
Solution:
Accessing a non-existing property of an object returns undefined.
Related Questions on Average

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

A). Hello

B). Undefined

C). Error

D). Hello

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

A). 'age' in person

B). person.has('age')

C). person.contains('age')

D). person.hasOwnProperty('age')

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

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

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

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() {} }

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

A). var obj = {};

B). var obj = [];

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How do you create an instance of the Car object using the constructor function?

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

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