Answer & Solution
let
is block scoped while var
is function scoped.
let
and var
in terms of scope?
let
is block scoped while var
is function 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
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 d; console.log(d); d = 15;
A). undefined
B). 15
C). null
D). ReferenceError
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?
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
In which scope are let
variables hoisted?
A). Function scope
B). Block scope
C). Global scope
D). Module scope
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
Which keyword should be used to declare variables that do not get re-assigned?
A). let
B). const
C). var
D). function
How can you avoid variable hoisting issues with let
?
A). Declare variables at the bottom of the code
B). Use var
instead
C). Declare variables at the top of their scope
D). Do not declare variables