There are a few new concepts which will not be familiar to most FORTRAN programmers. We will try to explain them to you here. Some of the concepts are unique to C++ and some are true both for C++ and for C. C++ is a language which is based on C, but includes many features that C does not have. We will point out when possible which features are unique to C++ .
One thing to notice when reading the examples below is that, unlike FORTRAN, the case of letters in variable names and program keywords matters. In other words, if you declare a variable called myVariable, you must not try to refer to it later as MYVARIABLE or MyVariable. The compiler considers these to be different variables.
You should also notice that you need to declare all of your variables(just as if you had used an IMPLICIT NONE in your FORTRAN program). Unlike FORTRAN or normal C where you need to declare all of your variables at the top of a routine, in C++ you can declare your variables(before you use them) anywhere in your program.