Can an identifier be a single character?

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

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 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

Are JavaScript identifiers case-sensitive?

A). Yes

B). No

C). Only in ES6

D). Only in strict mode

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

Which of these is an invalid identifier?

A). foo_bar

B). fooBar

C). foo-bar

D). foo$bar

Which of the following is a reserved word in JavaScript?

A). myVariable

B). function

C). let

D). number

Which of the following is an invalid identifier?

A). _variable

B). var$

C). 2variable

D). variable2

Is let a valid identifier in JavaScript?

A). Yes

B). No

C). Only in ES6

D). Only in non-strict mode