Data Types in JavaScript

The video tutorial introduces JavaScript data types, dividing them into primitive and reference types. Primitive types include strings, numbers, booleans, null, undefined, and symbols, while reference types encompass objects, arrays, and functions. The tutorial explains how JavaScript is dynamically typed, allowing variables to hold different types without errors. It also touches on TypeScript, which adds static typing to JavaScript. Practical coding examples demonstrate the use of the typeof operator to identify data types.

What are the two main categories of data types in JavaScript?

• Static and Dynamic

• Primitive and Reference

• Integer and Float

• String and Number

Which of the following is NOT a primitive data type in JavaScript?

• Array

• String

• Boolean

• Number

In JavaScript, what is the result of 'typeof null'?

• undefined

• null

• string

• object

Which data type in JavaScript is used to represent a sequence of characters?

• Symbol

• String

• Boolean

• Number

What is a characteristic of reference data types in JavaScript?

• They are accessed by reference.

• They are immutable.

• They are accessed by value.

• They are stored on the stack.

Which of the following is a reference data type in JavaScript?

• Number

• Array

• Boolean

• Symbol

What does the 'typeof' operator do in JavaScript?

• Converts data types

• Checks the type of a variable

• Declares a variable

• Assigns a value to a variable

What will 'typeof 42' return in JavaScript?

• undefined

• boolean

• number

• string

Which keyword is used to declare a variable that can be reassigned in JavaScript?

• var

• let

• const

• static

What is the purpose of type conversion in JavaScript?

• To store data on the stack

• To declare a new variable

• To access a variable by reference

• To change the data type of a variable