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

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 will typeof NaN return in JavaScript?

A). number

B). NaN

C). undefined

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

What is the result of typeof [] in JavaScript?

A). array

B). object

C). list

D). undefined

What will typeof null return in JavaScript?

A). null

B). undefined

C). object

D). number

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

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

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

A). number

B). boolean

C). string

D). object

In JavaScript, what will be the type of a variable x after x = 5 + true;?

A). number

B). string

C). boolean

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