using own function in writing a function

[behzad_shabani]

can I use a function (written by myself) in writing a new function?

[laserlight]

Yes.

[matsp]

Sure. Is this what you meant:

void func()
{
    printf("void newfunc()\{\n\tprintf(\"Hello, World\\n\");\n}\n");
}

Obviously, you may make this as complicated as you like, and output it to a file if you like.

[I know, this is probably NOT what you meant to ask for, but I couldn't resist answering a different one... ]

--
Mats

[behzad_shabani]

then, I should define which one first?

[matsp]

then, I should define which one first?

Doesn't really matter - it's a style issue. If you are only calling one from the other, then I personally prefer to put the outermost (called last) first, and then work in towards main. But I starting programming in Pascal many years ago, and in Pascal you are not meant to forward declare function unless one calls the other recursive manners.

--
Mats