What is the maximum length of an identifier?

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

Which characters are allowed in JavaScript identifiers?

A). Letters only

B). Letters and numbers only

C). Letters, numbers, $ and _

D). Any special characters

Can an identifier be a single character?

A). Yes

B). No

C). Only in ES5

D). Only in ES6

Can identifiers start with a digit in JavaScript?

A). Yes

B). No

C). Only in ES5

D). Only in strict mode

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

A). Syntax error

B). 5

C). 10

D). Reference error

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

A). undefined

B). null

C). 5

D). x

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 identifier is valid in strict mode?

A). public

B). _public

C). 123public

D). public$

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var