Which keyword is used to declare a read-only named constant?

What will be the output of the following code: let x = 10; { let x = 20; } console.log(x);?

A). 10

B). 20

C). undefined

D). ReferenceError

What happens if you try to access a let variable before its declaration?

A). Returns undefined

B). Throws a ReferenceError

C). Returns null

D). Returns an empty string

What is the value of a const variable once it is assigned?

A). Can be changed later

B). Cannot be changed later

C). Depends on the data type

D). Undefined initially

What will the following code output: { const a = 10; a = 20; }?

A). 10

B). 20

C). undefined

D). TypeError

Can const variables be reassigned in nested scopes?

A). Yes

B). No

C). Only if they are strings

D). Only in strict mode

What error will the following code produce: const PI; PI = 3.14;?

A). SyntaxError

B). TypeError

C). ReferenceError

D). No error

What is the scope of a variable declared with let?

A). Global

B). Function

C). Block

D). Object

What is the primary difference between var and let?

A). Scope

B). Initialization

C). Data type

D). Assignment

Can a const variable be declared without an initial value?

A). Yes

B). No

C). Only in strict mode

D). Only if it is an object

Which keyword should be used for a variable that might be reassigned?

A). const

B). let

C). var

D). function