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

Answer & Solution

Answer: Option C
Solution:
Reassigning a 'const' variable results in a TypeError because 'const' variables are immutable.
Related Questions on Average

How does 'let' handle variable re-declaration in the same scope?

A). Allows it

B). Silently ignores

C). Throws an error

D). Creates a new variable

Can 'const' be used to declare an array or object?

A). No, only primitives

B). Yes, but the reference can't change

C). Yes, and the content can't change

D). No

What is the default scope of variables declared with the 'var' keyword in JavaScript?

A). Block scope

B). Function scope

C). Module scope

D). Block and function scope

Which keyword allows block-scoped variable declaration?

A). var

B). let

C). const

D). Both B and C

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: console.log(a); var a = 50;

A). 50

B). undefined

C). Error

D). null

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

A). Creates a global variable

B). Creates a block-scoped variable

C). Creates a function-scoped variable

D). Throws an error

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

A). Global

B). Function

C). Loop block

D). Entire script

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 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