Which of the following is a reserved word in JavaScript?

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

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

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

Which is a correct identifier for a variable?

A). 9variable

B). variable-9

C). variable_9

D). variable 9

What is the maximum length of an identifier?

A). 255 characters

B). 31 characters

C). 64 characters

D). No limit

Which of the following is an invalid identifier?

A). _variable

B). var$

C). 2variable

D). variable2

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