Which identifier is valid in strict mode?

Which of the following is a reserved word in JavaScript?

A). myVariable

B). function

C). let

D). number

Can identifiers start with a digit in JavaScript?

A). Yes

B). No

C). Only in ES5

D). Only in strict mode

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

Can an identifier be a single character?

A). Yes

B). No

C). Only in ES5

D). Only in ES6

What is the maximum length of an identifier?

A). 255 characters

B). 31 characters

C). 64 characters

D). No limit

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 is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

Which of the following is a valid identifier name?

A). var

B). 123abc

C). _123abc

D). #abc123

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

A). undefined

B). null

C). 5

D). x

Are JavaScript identifiers case-sensitive?

A). Yes

B). No

C). Only in ES6

D). Only in strict mode