Given let a = "10"; let b = 20;, what is the result of a + b?

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 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

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

What is the result of typeof [] in JavaScript?

A). array

B). object

C). list

D). undefined

What will typeof NaN return in JavaScript?

A). number

B). NaN

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 will typeof null return in JavaScript?

A). null

B). undefined

C). object

D). number

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

A). null

B). number

C). undefined

D). object