Which characters are allowed in JavaScript identifiers?

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

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

Can JavaScript identifiers include spaces?

A). Yes

B). No

C). Only in ES6

D). Only in strings

Is let a valid identifier in JavaScript?

A). Yes

B). No

C). Only in ES6

D). Only in non-strict mode

Which of the following is a valid identifier?

A). if

B). else

C). null

D). value1

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 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

Which is a correct identifier for a variable?

A). 9variable

B). variable-9

C). variable_9

D). variable 9

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

A). undefined

B). null

C). 5

D). x