What are
the rules for giving
variable name ?​

Rules for naming variables:

- Variable names in Visual C++ can range from 1 to 255 characters. To make variable names portable to other environments stay within a 1 to 31 character range.

- All variable names must begin with a letter of the alphabet or an underscore ( _ ).  For beginning programmers, it may be easier to begin all variable names with a letter of the alphabet.

- After the first initial letter, variable names can also contain letters and numbers.  No spaces or special characters, however, are allowed.

- Uppercase characters are distinct from lowercase characters.  Using all uppercase letters is used primarily to identify constant variables.  

- You cannot use a C++ keyword (reserved word) as a variable name.

it is much more convenient for the consumer to order something online, rather than going to a store. it saves them time and money for them, especially if that item is not accessed easily.