Which is a correct identifier for a variable?

Which of the following is an invalid identifier?

A). _variable

B). var$

C). 2variable

D). variable2

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

Which of the following is a reserved word in JavaScript?

A). myVariable

B). function

C). let

D). number

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

A). undefined

B). null

C). 5

D). x

Which identifier is valid in strict mode?

A). public

B). _public

C). 123public

D). public$

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

Are JavaScript identifiers case-sensitive?

A). Yes

B). No

C). Only in ES6

D). Only in strict mode

Can identifiers start with a digit in JavaScript?

A). Yes

B). No

C). Only in ES5

D). Only in strict mode

Which of the following is a valid identifier?

A). if

B). else

C). null

D). value1