What is the output of the following code: var x = 5, x = 10;

Which of these is an invalid identifier?

A). foo_bar

B). fooBar

C). foo-bar

D). foo$bar

Are JavaScript identifiers case-sensitive?

A). Yes

B). No

C). Only in ES6

D). Only in strict mode

Which of the following is an invalid identifier?

A). _variable

B). var$

C). 2variable

D). variable2

Which of the following is a valid identifier name?

A). var

B). 123abc

C). _123abc

D). #abc123

What does the following code do: var $ = 5;

A). Throws an error

B). Creates a variable named $

C). Creates a variable named var

D). None of the above

Is let a valid identifier in JavaScript?

A). Yes

B). No

C). Only in ES6

D). Only in non-strict mode

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

Which of the following is a valid identifier?

A). if

B). else

C). null

D). value1

Which of the following is a reserved word in JavaScript?

A). myVariable

B). function

C). let

D). number

Which identifier is valid in strict mode?

A). public

B). _public

C). 123public

D). public$