JavaScript Data Types MCQ Questions and Answers

Practice these JavaScript Data Types MCQ questions and answers to test your understanding of primitive and non-primitive data types. This quiz covers String, Number, Boolean, Undefined, Null, Symbol, BigInt, Objects, and other important JavaScript concepts frequently asked in interviews and online assessments.

What Are JavaScript Data Types?

JavaScript data types define the kind of values that can be stored and manipulated within a program. Every variable in JavaScript contains a value that belongs to a specific data type.

Common JavaScript data types include String, Number, Boolean, Undefined, Null, Symbol, BigInt, and Object. Understanding these data types is essential for writing efficient JavaScript code and solving programming problems.

This JavaScript Data Types Quiz helps learners practice important concepts related to primitive and non-primitive data types through multiple-choice questions commonly asked in interviews and coding assessments.

Why Learn JavaScript Data Types?




Instructions

Topic- javascript data types

The test consists of 14 questions.

No negative marking for this test.

No Time limit

The pass percentage is 70%

The correct answer with a description will be displayed after the answer has been marked.

Submit the test to calculate your score once you are done with all the questions.

Complexity Level- Moderate




Q1: Null is a valid data type in Javascript:

Select True or False.











Q2: What will be the console output of the below JS code:

let a;
console.log(a);















Q3: Which of the following is NOT a valid data type in JS?















Q4: What will be the console output of the below JS code?

let a=null;
console.log(a);















Q5: What will be the console output of the below JS code?

let a=hello;
console.log(a);















Q6: What will be the console output of the below JS code?

let a="hello";
console.log(a);


















Q7: What will be the console output of the below JS code?

let a="8"+"8";
console.log(a);


















Q8: Identify whether the below Javascript code is a valid or an invalid code:

let a=[34,"hello",false, 4599];














Q9: What will be the console output of the below JS code?

let a="8"/8;
console.log(a);


















Q10: The below JS code is an ______

let a = {name:"Sarah", age:24, address: "7 north block"}


















Q11: What will be the console output of the below JS code?

let a=34;
let b=56;
console.log(a=b);


















Q12: What will be the console output of the below javascript code?

let a = false;
console.log(a);


















Q13: What will be the console output of the below javascript code?

let a="8"+8+8;
console.log(a);


















Q14: What will be the console output of the below javascript code?

let a="8"+8;
console.log(a+a);































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Frequently Asked Questions (FAQs)

What are JavaScript data types?

JavaScript data types define the type of value stored in a variable. Common data types include String, Number, Boolean, Undefined, Null, Symbol, BigInt, and Object.

How many data types are there in JavaScript?

JavaScript provides several built-in data types, including primitive types such as String, Number, Boolean, Undefined, Null, Symbol, BigInt, and the Object data type.

What is the difference between primitive and non-primitive data types?

Primitive data types store a single value directly, while non-primitive data types such as Objects and Arrays store collections of values and are accessed through references.

Why are JavaScript data types important?

Understanding data types helps developers write accurate code, avoid type-related bugs, and improve program performance and maintainability.

Is this JavaScript Data Types Quiz useful for interviews?

Yes. JavaScript data types are a fundamental interview topic and frequently appear in coding tests, developer interviews, and technical assessments.