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

Which of the following values is considered falsy in JavaScript?

A). 1

B). 0

C). 0

D). {}

What is the type of the value returned by parseFloat('3.14abc')?

A). number

B). string

C). NaN

D). undefined

What will typeof null return in JavaScript?

A). null

B). undefined

C). object

D). number

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 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 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

What is the result of typeof [] in JavaScript?

A). array

B). object

C). list

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 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