Answer & Solution
let
is hoisted but not initialized in the block scope, resulting in a ReferenceError
when accessed before declaration.
let f = 10; if (true) { console.log(f); let f = 20; }
let
is hoisted but not initialized in the block scope, resulting in a ReferenceError
when accessed before declaration.
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 is the scope of a variable declared with let
inside a loop?
A). Global scope
B). Function scope
C). Block scope
D). Module scope
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 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 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
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 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?
{ 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