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

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 of the following values is considered falsy in JavaScript?

A). 1

B). 0

C). 0

D). {}

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 will typeof null return in JavaScript?

A). null

B). undefined

C). object

D). number

What does the parseInt function do in JavaScript?

A). Converts a number to a string

B). Converts a string to an integer

C). Converts a boolean to a number

D). Converts an array to a number

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

A). number

B). string

C). boolean

D). undefined

What is the type of the value returned by JSON.parse('null')?

A). null

B). string

C). object

D). undefined

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

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