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

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

A). null

B). number

C). undefined

D). object

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

Which operator is used to determine the type of a variable in JavaScript?

A). typeof

B). instanceof

C). type

D). isType

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 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

Which of the following values is considered falsy in JavaScript?

A). 1

B). 0

C). 0

D). {}

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

How can you check if a variable is an array in JavaScript?

A). typeof variable === 'array'

B). Array.isArray(variable)

C). variable instanceof array

D). variable.constructor === array