What is the purpose of using block scope in JavaScript?

What will be the output of the code above?

A). A. 10

B). B. 20

C). C. Error

D). D. Undefined

Which keyword is used to declare a constant array in JavaScript?

A). A. let

B). B. const

C). C. var

D). D. array

Which keyword is used to declare block-scoped variables in JavaScript?

A). A. var

B). B. let

C). C. const

D). D. block

What will be logged to the console after 1 second?

A). A. 0 1 2

B). B. 3 3 3

C). C. 0 0 0

D). D. Error

Which statement is true regarding the const keyword in JavaScript?

A). A. Constants declared with const are hoisted

B). B. Constants declared with const can be reassigned

C). C. Constants declared with const have global scope

D). D. Constants declared with const are immutable

What will be the output of the code above?

A). A. 30

B). B. 31

C). C. Error

D). D. Undefined

What happens if you try to reassign a value to a constant declared using const?

A). A. SyntaxError

B). B. TypeError

C). C. ReferenceError

D). D. No error, value is reassigned

Which of the following is NOT an example of a block in JavaScript?

A). A. Function body

B). B. if statement body

C). C. while loop body

D). D. Object literal

Which of the following statements is true about constants declared using const?

A). A. They can be reassigned multiple times

B). B. They are hoisted to the top

C). C. They are mutable

D). D. They are immutable

What does the const keyword signify in JavaScript?

A). A. Constant variable

B). B. Mutable variable

C). C. Global variable

D). D. Block-scoped variable