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

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

Which of the following will cause an error?

A). let a = 10; a = 20;

B). const a = 10; a = 20;

C). var a = 10; a = 20;

D). None of the above

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

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 a valid variable name in JavaScript?

A). 2name

B). _name

C). #name

D).

Which keyword is used to declare a variable in JavaScript?

A). var

B). let

C). const

D). All of the above

What will be the output of the following code?

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

A). 11

B). 11

C). 5

D). 6

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

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

Which of the following is true about 'const' variables in JavaScript?

A). They can be redeclared

B). They cannot be reassigned

C). They can be reassigned

D). They are always undefined