Can JavaScript identifiers include spaces?

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

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

A). No error

B). Syntax error

C). Logical error

D). Runtime error

Which of the following is an invalid identifier?

A). _variable

B). var$

C). 2variable

D). variable2

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

A). undefined

B). null

C). 5

D). x

Can identifiers start with a digit in JavaScript?

A). Yes

B). No

C). Only in ES5

D). Only in strict mode

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

Is let a valid identifier in JavaScript?

A). Yes

B). No

C). Only in ES6

D). Only in non-strict mode

What is the maximum length of an identifier?

A). 255 characters

B). 31 characters

C). 64 characters

D). No limit

Which identifier is valid in strict mode?

A). public

B). _public

C). 123public

D). public$

Which characters are allowed in JavaScript identifiers?

A). Letters only

B). Letters and numbers only

C). Letters, numbers, $ and _

D). Any special characters