Answer & Solution
let in the function test is in the TDZ, so trying to access e before its declaration results in a ReferenceError.
let e = 25; function test() { console.log(e); let e = 30; } test();
let in the function test is in the TDZ, so trying to access e before its declaration results in a 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 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
Which keyword should be used to declare variables that do not get re-assigned?
A). let
B). const
C). var
D). function
In which scope are let variables hoisted?
A). Function scope
B). Block scope
C). Global 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
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 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?
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