Thread: Need simple help please!!

My code is A LOT shorter that the book's code, and it's even easier to understand!

True.

I dont understand anything about how the first program works, please explain to me!

Which is why the first program is written the way it is. It's meant to teach you a bit about functions and good program design.

Why do you need to be explained the first program when it's practically the same as the second program? The only differences are that you calculate the area in the main function, and the program calculates it in a seperate function, FindArea(). (And you have a system("pause");, but that's not important.)

at this point:

Code:

areaOfYard= FindArea(lengthOfYard, widthOfYard);

the code for the FindArea function is called along with the values of lengthOfYard and widthOfYard, so you will get this:

Code:

int FindArea(int l, int w)
{
     return l * w;
}

with l == lengthOfYard and w == widthOfYard

The int part that I've highlighted is the return type from the function. This means the function has to return to the point where it was called with an int value. FindArea returns the value of l * w, so now we get :

Code:

areaOfYard = l*w

I hope thats sort of clear, all you are really doing is replacing "FindArea" with the code specified in the FindArea function.

the first program takes advantage of functions.

treat FindArea(lengthOfYard, widthOfYard) kind of like a shortcut.
when the computer sees it, it goes looking for how to handle it.

the shortcut is defined outside of the main loop, at the bottom. how it works is this:


int FindArea(int l, int w) /*this names the function and shows what variable goes in it. the 'int' at first tells what kind of variable the function will return (in this case, when it solves for area, the answer will be an int, so it returns an int). the int l and int w in parenthesis tell what will be put into the function to be used (in this example, the function is solving for area using length and width, so you want to put the length and width from your program into the function). */

{
return l * w; /*this is where the work is done. your function multiplies l by w and sends that answer back to your main loop. Ideally, functions would hold large amounts of data that would be inconvenient to have to write over and over again in your program, so you put it all in a function and just use the function in your program rather than duplicating the code every instance its used. */
}


so in your main, you want it to multiply length times width, so you put whatever variable is holding length and width into the function, in this case lengthOfYard and widthOfYard.