How does 'let' differ from 'var' in terms of 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 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: console.log(a); var a = 50;

A). 50

B). undefined

C). Error

D). null

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

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

A). Yes

B). No

C). Only in functions

D). Only in loops

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

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: let y = 10; let y = 20; console.log(y);

A). 10

B). 20

C). Error

D). undefined