Q
What will happen if you declare a variable without 'var', 'let', or 'const'?

Answer & Solution

Answer: Option A
Solution:
Declaring a variable without 'var', 'let', or 'const' creates a global variable, which can lead to potential bugs.
Related Questions on Average

What will be the output of the following code: if (true) { let b = 60; } console.log(b);

A). 60

B). undefined

C). Error

D). null

How do 'var' declarations handle hoisting?

A). They are not hoisted

B). Only the assignment is hoisted

C). Only the declaration is hoisted

D). Both declaration and assignment are hoisted

What will be the output of the following code: const z = 30; z = 40; console.log(z);

A). 30

B). 40

C). Error

D). undefined

What will be the output of the following code: let y = 10; let y = 20; console.log(y);

A). 10

B). 20

C). Error

D). undefined

What will be the output of the following code: var x = 5; var x = 10; console.log(x);

A). 5

B). 10

C). Error

D). undefined

What is the scope of a variable declared with 'let' inside a loop?

A). Global

B). Function

C). Loop block

D). Entire script

Which keyword is used for declaring variables that should not change?

A). var

B). let

C). const

D). all of the above

What will be the output of the following code: const d = 90; d = 100; console.log(d);

A). 90

B). 100

C). Error

D). undefined

What will be the output of the following code: let c = 70; { let c = 80; console.log(c); } console.log(c);

A). 70 80 80

B). 80 80

C). Error

D). 70 80

Can you re-declare a variable using 'const' in the same scope?

A). Yes

B). No

C). Only in functions

D). Only in loops