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

Which keyword allows block-scoped variable declaration?

A). var

B). let

C). const

D). Both B and C

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: 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: if (true) { let b = 60; } console.log(b);

A). 60

B). undefined

C). Error

D). null

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

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: 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 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