Can an identifier be a single character?

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

Which of the following is a valid identifier?

A). if

B). else

C). null

D). value1

Which characters are allowed in JavaScript identifiers?

A). Letters only

B). Letters and numbers only

C). Letters, numbers, $ and _

D). Any special characters

Which of the following is a reserved word in JavaScript?

A). myVariable

B). function

C). let

D). number

What will happen if you declare a variable with the name undefined?

A). Syntax error

B). Declares a variable

C). Throws a runtime error

D). Reassigns undefined

Are JavaScript identifiers case-sensitive?

A). Yes

B). No

C). Only in ES6

D). Only in strict mode

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

Which of the following is an invalid identifier?

A). _variable

B). var$

C). 2variable

D). variable2

Which of these is an invalid identifier?

A). foo_bar

B). fooBar

C). foo-bar

D). foo$bar

Which of the following is a valid identifier name?

A). var

B). 123abc

C). _123abc

D). #abc123