How does 'let' differ from 'var' in terms of scope?

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

A). Yes

B). No

C). Only in functions

D). Only in loops

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

A). 50

B). undefined

C). Error

D). null

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

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

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

Which keyword allows block-scoped variable declaration?

A). var

B). let

C). const

D). Both B and C

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 will be the output of the following code: var e = 110; if (true) { var e = 120; } console.log(e);

A). 110

B). 120

C). Error

D). undefined

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