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
What is the result of typeof [] in JavaScript?
A). array
B). object
C). list
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 is the type of the value returned by parseFloat('3.14abc')?
A). number
B). string
C). NaN
D). undefined
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 type of the value returned by JSON.parse('null')?
A). null
B). string
C). object
D). undefined
Given let a = '10'; let b = 20;, what is the result of a + b?
A). 30
B). 1020
C). 30
D). NaN
Which operator is used to determine the type of a variable in JavaScript?
A). typeof
B). instanceof
C). type
D). isType
What will be the result of typeof function() {} in JavaScript?
A). function
B). object
C). undefined
D). method
Given the code: let y = 10; y = true;, what is the type of y after execution?
A). number
B). boolean
C). string
D). object
Which type conversion happens automatically in the expression 3 + '5'?
A). Number to String
B). String to Number
C). Boolean to String
D). Number to Boolean