Can an identifier be a single character?

Which of the following is a valid identifier name?

A). var

B). 123abc

C). _123abc

D). #abc123

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 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

Can identifiers start with a digit in JavaScript?

A). Yes

B). No

C). Only in ES5

D). Only in strict mode

Which is a correct identifier for a variable?

A). 9variable

B). variable-9

C). variable_9

D). variable 9

Which characters are allowed in JavaScript identifiers?

A). Letters only

B). Letters and numbers only

C). Letters, numbers, $ and _

D). Any special characters

Which identifier is valid in strict mode?

A). public

B). _public

C). 123public

D). public$

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

What is the maximum length of an identifier?

A). 255 characters

B). 31 characters

C). 64 characters

D). No limit