Where should let variables be declared to avoid TDZ issues?

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

What will be the output of the following code?

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

A). 20

B). undefined

C). null

D). ReferenceError

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 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 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

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

A). 10

B). 20

C). undefined

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?

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

A). undefined

B). 15

C). null

D). ReferenceError