let?
let variables at the top of their block scope avoids TDZ issues and hoisting-related errors.
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 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
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?
{ console.log(b); let b = 20; }A). 20
B). undefined
C). null
D). ReferenceError
In which scope are let variables hoisted?
A). Function scope
B). Block scope
C). Global scope
D). Module scope
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 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
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 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