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

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

A). No difference

B). Function-scoped

C). Block-scoped

D). Global-scoped

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: var e = 110; if (true) { var e = 120; } console.log(e);

A). 110

B). 120

C). Error

D). undefined

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

Which of the following statements is true about 'const'?

A). It allows re-declaration

B). It allows reassignment

C). It is block-scoped

D). It is function-scoped

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

A). Global

B). Function

C). Loop block

D). Entire script

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

A). Yes

B). No

C). Only in functions

D). Only in loops