What will be the output of the following code?

var x = 5; var y = 6; var z = x + y;

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

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

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

What will be the output of the following code?

let x; console.log(x);

A). null

B). undefined

C). 0

D). NaN

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

A). myVar

B). $myVar

C). _myVar

D). 123myVar

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

A). var

B). let

C). const

D). Both let and const

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 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

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

What is the correct syntax for declaring a variable in JavaScript?

A). let myVar = 5;

B). myVar let = 5;

C). 5 = let myVar;

D). let = myVar 5;