What will be the result of using a reserved word as an identifier?

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

Which of these is an invalid identifier?

A). foo_bar

B). fooBar

C). foo-bar

D). foo$bar

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

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

Are JavaScript identifiers case-sensitive?

A). Yes

B). No

C). Only in ES6

D). Only in strict mode

What will the following code output: var x; x = 5; var y = x;

A). undefined

B). null

C). 5

D). x

What will happen if you declare a variable with the name undefined?

A). Syntax error

B). Declares a variable

C). Throws a runtime error

D). Reassigns undefined

Can identifiers start with a digit in JavaScript?

A). Yes

B). No

C). Only in ES5

D). Only in strict mode

Which of the following is a reserved word in JavaScript?

A). myVariable

B). function

C). let

D). number