Which identifier is valid in strict mode?

What is the maximum length of an identifier?

A). 255 characters

B). 31 characters

C). 64 characters

D). No limit

Which characters are allowed in JavaScript identifiers?

A). Letters only

B). Letters and numbers only

C). Letters, numbers, $ and _

D). Any special characters

Is let a valid identifier in JavaScript?

A). Yes

B). No

C). Only in ES6

D). Only in non-strict mode

Which of these is an invalid identifier?

A). foo_bar

B). fooBar

C). foo-bar

D). foo$bar

What is a valid identifier in JavaScript?

A). 123abc

B). abc123

C). let

D). var

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

A). undefined

B). null

C). 5

D). x

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 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