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
What is the result of typeof [] in JavaScript?
A). array
B). object
C). list
D). undefined
In JavaScript, what will be the type of a variable x after x = 5 + true;?
A). number
B). string
C). boolean
D). undefined
Which operator is used to determine the type of a variable in JavaScript?
A). typeof
B). instanceof
C). type
D). isType
Given let a = '10'; let b = 20;, what is the result of a + b?
A). 30
B). 1020
C). 30
D). NaN
What will typeof NaN return in JavaScript?
A). number
B). NaN
C). undefined
D). object
What is the initial type of a variable declared with let a;?
A). null
B). number
C). undefined
D). object
What is the type of the value returned by JSON.parse('null')?
A). null
B). string
C). object
D). undefined
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 typeof null return in JavaScript?
A). null
B). undefined
C). object
D). number