>> so if the program or any program just require anything that has to do with EOF i have to do the F6 thing right? and if it doesnt call eof as an argument of any kind then i wont need to press F6 ever? <<

Yes. Pretty much. You can also use a file as input. This is called redirection. In this case, the program will receive EOF (which stands for "end of file") at the end of the file. This example shows how to run a program using file.txt as the input.
Code:
>yourprogram < file.txt
>> oh sorry i forgot also one last thing, is there a way to set dev c++ to do the F6 thing automatically whenever eof is called? <<

No. How would it know when to supply the EOF? The EOF allows you to tell the program that you have finished supplying input. If your program only expects a single line of input, it might use the new line character to tell it when the input is complete.