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

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

A). let

B). var

C). const

D). static

What is the temporal dead zone in ES6?

A). Time between function calls

B). Period between variable declaration and initialization

C). Time between two loops

D). Interval between event listeners

Can const be used for objects and arrays?

A). No

B). Yes

C). Only for arrays

D). Only for objects

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

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 allows block-level scope in ES6?

A). var

B). let

C). function

D). var and function

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

What will the following code output: { let y = 5; { let y = 10; console.log(y); } }?

A). 5

B). 10

C). undefined

D). ReferenceError

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

A). 3

B). 5

C). undefined

D). ReferenceError