Q
Which operator is used to determine the type of a variable in JavaScript?

Answer & Solution

Answer: Option A
Solution:
The typeof operator returns a string indicating the type of the unevaluated operand.
Related Questions on Average

What will be the result of the following code: let z = '123'; z = Number(z); console.log(typeof z);?

A). string

B). number

C). undefined

D). boolean

What will be the result of typeof function() {} in JavaScript?

A). function

B). object

C). undefined

D). method

What does the isNaN function do?

A). Checks if a value is not a number

B). Converts a value to a number

C). Checks if a value is a number

D). Converts a value to NaN

Given the code: let y = 10; y = true;, what is the type of y after execution?

A). number

B). boolean

C). string

D). object

What does it mean that JavaScript is dynamically typed?

A). Variables do not have types

B). Variables can change type

C). Variables must be declared with a type

D). Variables cannot change type

Given let a = '10'; let b = 20;, what is the result of a + b?

A). 30

B). 1020

C). 30

D). NaN

What happens when you add a number and a string in JavaScript?

A). An error is thrown

B). The number is converted to a string

C). The string is converted to a number

D). Both are converted to boolean

What is the initial type of a variable declared with let a;?

A). null

B). number

C). undefined

D). object

What will typeof NaN return in JavaScript?

A). number

B). NaN

C). undefined

D). object

What is the result of typeof [] in JavaScript?

A). array

B). object

C). list

D). undefined