Answer & Solution
Answer: Option A
Solution:
The isNaN function determines if a value is NaN (Not-a-Number).
Q
What does the isNaN function do?
Related Questions on Average
Which operator is used to determine the type of a variable in JavaScript?
A). typeof
B). instanceof
C). type
D). isType
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
Given let a = '10'; let b = 20;, what is the result of a + b?
A). 30
B). 1020
C). 30
D). NaN
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
What is the result of the following code: let x = 5; x = 'hello'; console.log(typeof x);?
A). number
B). string
C). undefined
D). object
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 type of the value returned by parseFloat('3.14abc')?
A). number
B). string
C). NaN
D). undefined