Q
What will be the output of the following code?
console.log(a); let a = 10;

Answer & Solution

Answer: Option D
Solution:
let
declarations are hoisted but not initialized, so accessing a before its declaration results in a ReferenceError.
Related Questions on Average

Which of the following is true about let declarations?

A). They are hoisted and initialized at the top of their scope

B). They are hoisted but not initialized

C). They are not hoisted at all

D). They are function scoped

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

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 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

In which scope are let variables hoisted?

A). Function scope

B). Block scope

C). Global scope

D). Module scope

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 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 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 f = 10; if (true) { console.log(f); let f = 20; }

A). 10

B). 20

C). undefined

D). ReferenceError