Question

Check the validity of the following identifiers:

(i) Mybook (ii) 2rno (iii) z2td (iv) date_2 (v) data-cs

Give the reason why some of these identifiers are invalid​

Answer 1

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1. Mybook is a valid identifier.
2. 2rno is an invalid identifier. Reason:- identifier name must not start with a digit.
3. z2td is a valid identifier.
4. date_2 is a valid identifier.
5. data-cs is an invalid identifier. Reason:- Hyphens are not allowed while naming an identifier.