Is let a valid identifier in JavaScript?

Which of the following is a valid identifier name?

A). var

B). 123abc

C). _123abc

D). #abc123

Can an identifier be a single character?

A). Yes

B). No

C). Only in ES5

D). Only in ES6

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

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

What is the output of the following code: var x = 5, x = 10;

A). Syntax error

B). 5

C). 10

D). Reference error

Which of the following is a valid identifier?

A). if

B). else

C). null

D). value1

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

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

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

A). undefined

B). null

C). 5

D). x