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

Which of the following statements about const and objects is true?

A). Objects declared with const are immutable

B). Properties of objects declared with const can be changed

C). The reference of objects declared with const can be changed

D). const cannot be used with objects

Are variables declared with let and const accessible before they are declared?

A). Yes

B). No

C). Only in strict mode

D). Only if they are numbers

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

A). SyntaxError

B). TypeError

C). ReferenceError

D). No error

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 output of the following code: let z = 3; z = 5; console.log(z);?

A). 3

B). 5

C). undefined

D). ReferenceError

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

A). 10

B). 20

C). undefined

D). TypeError

Can const be used for objects and arrays?

A). No

B). Yes

C). Only for arrays

D). Only for objects

Can const variables be reassigned in nested scopes?

A). Yes

B). No

C). Only if they are strings

D). Only in strict mode

What is the primary difference between var and let?

A). Scope

B). Initialization

C). Data type

D). Assignment

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

A). let

B). var

C). const

D). static