Why " abc" is not legal. identifier

Answer 1

It is a legal identifier, but it's a poorly named one. abc doesn't mean anything, it doesn't tell you what it contains nor what to use it for.

Answer 2

whenever you are naming variable it's good practice that you name the variable so that it make sense.abc is not give you any kind of hint that what was it's use or what it's purpose in the code.so naming the variable will allow you and other to understand the problem when you get caught in an error.when if you use abc you first need to find out what is abc actually.but that doesn't mean you can not use abc as identifier.