Q
What will be the output of the following code?
let d; console.log(d); d = 15;

Answer & Solution

Answer: Option A
Solution:
let declarations are hoisted and the variable is in the TDZ until the declaration is executed, so it logs undefined.
Related Questions on Average

Which statement about let and const is correct?

A). Both are block scoped, but only let can be re-assigned

B). Both are block scoped, but only const can be re-assigned

C). Only const is block scoped

D). Both are not block scoped

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 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 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 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

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

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 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 will be the output of the following code?

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

A). undefined

B). 10

C). null

D). ReferenceError

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