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

What will be the output of the following code?

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

A). 20

B). undefined

C). null

D). ReferenceError

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 will be the output of the following code?

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

A). undefined

B). 10

C). null

D). ReferenceError

What is the scope of a variable declared with let inside a loop?

A). Global scope

B). Function scope

C). Block scope

D). Module scope

Where should let variables be declared to avoid TDZ issues?

A). At the top of the global scope

B). At the bottom of their block scope

C). At the top of their block scope

D). Anywhere in the code

What will be the output of the following code?

let c = 5; { let c = 10; console.log(c); }

A). 5

B). 10

C). ReferenceError

D). undefined

What will be the output of the following code?

let h = 40; { console.log(h); h = 45; } console.log(h);

A). 40 45

B). 45 45

C). undefined undefined

D). ReferenceError 45

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?

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?

let i = 50; { let i = 55; console.log(i); } console.log(i);

A). 50 50

B). 55 50

C). 50 55

D). ReferenceError