What will be the output of the following code?

{ console.log(b); let b = 20; }

What will be the output of the following code?

let d; console.log(d); d = 15;

A). undefined

B). 15

C). null

D). ReferenceError

What is the 'temporal dead zone'?

A). The period during which a variable is declared but not yet initialized

B). The time when the variable is accessible throughout the program

C). The period after variable initialization

D). None of the above

What is the difference between let and var in terms of scope?

A). let is function scoped, var is block scoped

B). let is block scoped, var is function scoped

C). Both are function scoped

D). Both are block scoped

What happens when you try to re-declare a let variable in the same scope?

A). It reassigns the value

B). It throws a SyntaxError

C). It re-declares the variable

D). It throws a TypeError

What will be the output of the following code?

let e = 25; function test() { console.log(e); let e = 30; } test();

A). 25

B). 30

C). undefined

D). ReferenceError

What will be the output of the following code?

console.log(a); let a = 10;

A). undefined

B). 10

C). null

D). ReferenceError

Which keyword should be used to declare variables that do not get re-assigned?

A). let

B). const

C). var

D). function

What will be the output of the following code?

for (let i = 0; i < 3; i++) { setTimeout(() => console.log(i), 0); }

A). 0 0 0

B). 3 3 3

C). 0 1 2

D). ReferenceError

In which scope are let variables hoisted?

A). Function scope

B). Block scope

C). Global scope

D). Module scope

What is the advantage of using let over var?

A). let allows for function scoping

B). let does not get hoisted

C). let avoids issues related to the temporal dead zone

D). let is globally scoped