Can JavaScript identifiers include spaces?

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

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 valid identifier?

A). if

B). else

C). null

D). value1

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

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 a valid identifier name?

A). var

B). 123abc

C). _123abc

D). #abc123

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

A). Syntax error

B). 5

C). 10

D). Reference error

Can an identifier be a single character?

A). Yes

B). No

C). Only in ES5

D). Only in ES6