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

What will be logged to the console?

A). A. 'John'

B). B. 'Jane'

C). C. Error

D). D. Undefined

What will be the output of the code above?

A). A. 30

B). B. 31

C). C. Error

D). D. Undefined

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 of the following statements is true about block scope in JavaScript?

A). A. Variables declared with let have global scope

B). B. Variables declared with let have function scope

C). C. Variables declared with let are block-scoped

D). D. Variables declared with let are hoisted

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

What will be the output of the code above?

A). A. [1, 2, 3, 4]

B). B. [1, 2, 3]

C). C. [1, 2, 3, 4, 5]

D). D. Error

What is the purpose of using block scope in JavaScript?

A). A. To declare constants

B). B. To prevent variable hoisting

C). C. To improve code performance

D). D. To create global variables

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

A). A. let

B). B. const

C). C. var

D). D. array

What is the primary difference between const and let in JavaScript?

A). A. const variables can be reassigned

B). B. let variables are block-scoped

C). C. const variables are hoisted

D). D. let variables are immutable