Which of the following will cause an error?

What is hoisting in JavaScript?

A). Function call before declaration

B). Variable declared at the top

C). Variable and function declaration are moved to the top

D). Variable scope

Which of the following is correct about variable scope in JavaScript?

A). var is block-scoped

B). let is function-scoped

C). const is block-scoped

D). All variables are global

Can variables declared with 'var' be redeclared in the same scope?

A). Yes

B). No

C). Only inside a function

D). Only inside a loop

Which of the following is a valid variable name in JavaScript?

A). 2name

B). _name

C). #name

D).

Which statement is true about variables in JavaScript?

A). They must be declared before use

B). They can only hold numbers

C). They are statically typed

D). They are strongly typed

Can you reassign a value to a variable declared with let?

A). Yes

B). No

C). Only in strict mode

D). Only inside a block

Which keyword should be used to declare a block-scoped variable?

A). var

B). let

C). const

D). Both let and const

Which of the following is NOT a valid variable name in JavaScript?

A). myVar

B). $myVar

C). _myVar

D). 123myVar

What will be the output of the following code?

var a = 1; { var a = 2; } console.log(a);

A). 1

B). 2

C). undefined

D). ReferenceError

What will be the output of the following code?

const a = 10; a = 20; console.log(a);

A). 10

B). 20

C). Error

D). undefined