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

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 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 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

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

Can const be used for objects and arrays?

A). No

B). Yes

C). Only for arrays

D). Only for objects

What is the primary difference between var and let?

A). Scope

B). Initialization

C). Data type

D). Assignment

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

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

A). SyntaxError

B). TypeError

C). ReferenceError

D). No error

What is the scope of a variable declared with let?

A). Global

B). Function

C). Block

D). Object

Which keyword allows block-level scope in ES6?

A). var

B). let

C). function

D). var and function