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

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

Can a let variable be redeclared in the same scope?

A). Yes

B). No

C). Only if it is a string

D). Only if it is a number

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

A). const

B). let

C). var

D). 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

Can const be used for objects and arrays?

A). No

B). Yes

C). Only for arrays

D). Only for objects

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 primary difference between var and let?

A). Scope

B). Initialization

C). Data type

D). Assignment

Can a variable declared with let be hoisted?

A). Yes, partially

B). No

C). Yes, fully

D). Only in strict mode

Which keyword allows block-level scope in ES6?

A). var

B). let

C). function

D). var and function

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

A). 5

B). 10

C). undefined

D). ReferenceError