well i forget what its called but to add 1 to a variable such as in a loop you can go ++variablename to get it to change right away or variablename++ to get it to change just a bit later. you can also use -- in the same way to subtract1 from variables.

They're called the increment and decrement operators

That's why the language is "C++," which stands for "an increment better than C" or something like that.