Which operator is used to determine the type of a variable in JavaScript?
A). typeof
B). instanceof
C). type
D). isType
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 initial type of a variable declared with let a;?
A). null
B). number
C). undefined
D). object
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 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
Given let a = '10'; let b = 20;, what is the result of a + b?
A). 30
B). 1020
C). 30
D). NaN
What is the type of the value returned by parseFloat('3.14abc')?
A). number
B). string
C). NaN
D). undefined
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 is the type of the value returned by JSON.parse('null')?
A). null
B). string
C). object
D). undefined
What will typeof NaN return in JavaScript?
A). number
B). NaN
C). undefined
D). object