Answer & Solution
h
logs 40
from the outer scope, and the second logs the updated value 45
.
let h = 40; { console.log(h); h = 45; } console.log(h);
h
logs 40
from the outer scope, and the second logs the updated value 45
.
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
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
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
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
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 f = 10; if (true) { console.log(f); let f = 20; }
A). 10
B). 20
C). undefined
D). ReferenceError
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