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

Can const be used for objects and arrays?

A). No

B). Yes

C). Only for arrays

D). Only for objects

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

A). let

B). var

C). const

D). static

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

A). 5

B). 10

C). undefined

D). ReferenceError

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

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 allows block-level scope in ES6?

A). var

B). let

C). function

D). var and function

Can a variable declared with let be hoisted?

A). Yes, partially

B). No

C). Yes, fully

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 should be used for a variable that might be reassigned?

A). const

B). let

C). var

D). function

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