Answer & Solution
let creates a new i within the block, logging 55, while the outer i remains 50.
let i = 50; { let i = 55; console.log(i); } console.log(i);
let creates a new i within the block, logging 55, while the outer i remains 50.
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 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(b); let b = 20; }
A). 20
B). undefined
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 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
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
Which keyword should be used to declare variables that do not get re-assigned?
A). let
B). const
C). var
D). function
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
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