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

What will be the result of using a reserved word as an identifier?

A). No error

B). Syntax error

C). Logical error

D). Runtime error

Which of the following is a valid identifier?

A). if

B). else

C). null

D). value1

Can an identifier be a single character?

A). Yes

B). No

C). Only in ES5

D). Only in ES6

Are JavaScript identifiers case-sensitive?

A). Yes

B). No

C). Only in ES6

D). Only in strict mode

Which of the following is a valid identifier name?

A). var

B). 123abc

C). _123abc

D). #abc123

Which of the following is a reserved word in JavaScript?

A). myVariable

B). function

C). let

D). number

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

Which of the following is an invalid identifier?

A). _variable

B). var$

C). 2variable

D). variable2

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

A). Syntax error

B). 5

C). 10

D). Reference error

Which is a correct identifier for a variable?

A). 9variable

B). variable-9

C). variable_9

D). variable 9