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

What is the primary difference between var and let?

A). Scope

B). Initialization

C). Data type

D). Assignment

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

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

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

Which keyword allows block-level scope in ES6?

A). var

B). let

C). function

D). var and function

Can const be used for objects and arrays?

A). No

B). Yes

C). Only for arrays

D). Only for objects

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 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 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