Conventions (Rules) for creating Variable

1. First Character of variable should be an alphabet

2. The name of variables can be in lower case as well as upper case.

3. Two or more variables cannot have same name.

4. It Cannot contain any space in between variable name.

5. It cannot contain Period Sign ( . )

6. We cannot use keywords as variable names i.e. variable name like int, float, if are invalid.

7. No special symbol is allowed in variable name.

8. A variable name should not be more than 40 characters, but it is safer to declare variable name as short as possible

int a,b,c;
int a=10, b=20, c;