Thread: Dis-Function Issues

I have been learning C programming on my own and I am just trying to get the hang of functions. And so far I seem to be missing something. Maybe just a push in the right direction.

Code:

#include <stdio.h>


#define PI 3.14


int area_Circle(int a, int r);








int main(){


 float r, a;








while (printf("Enter a number to find the area of a circle,\nEnter Zero if you would like to quit!:")){




 scanf("%f", &r);
 if("%f", r>0)
 {
  
  printf("The area is %f\n", a);
 continue;
 }




 else


   {


     "%f", r < 1;
     break;


   }
   


return 1;
}




int area_Circle(int a, int r);
{
 a;
 a = PI *r*r;
return a;     
    
}


}

I though this would work this way, As I defined PI under the "#include" statement. Please help me understand what I missing here. Thanks in advance to any help.

Also, you have to actually call the function if you want it to happen. You need to look at your if statements, because they work but don't make a lot of sense.

As others have indicated, you are having problems without trying to use functions.
Where does the function main() on line 16 end?
Where does the while loop that begins on line 28 end?
What is the condition for the while loop that begins on line 28? (See for example C loops)
I would read the tutorials found here or at other sites.

Sorry Fixing white space now.

And as far as my trouble goes. I am having a slight problem understanding why the function I defined at the bottom is not working. Meaning when I run the code I get 0.00000 as the area of a circle. (PI*r*r) is not doing what I tell it to do inside the fuction. So I guess the right question is?; why is my function

Code:

intarea_Circle(inta, intr);

not woking?

I think you think the function actually happens. I would like to know why you think that.

I don't think your using continue and break how you think

while(number!=0){
if(r>0){
a=area_Circle(int a, int r);
printf("The area is %f\n", a);
}
else

etc etc.

your using <1 as a break from the loop, why not just your while condition to <1 then

Okay so I have removed the while loop and the if else statement. All that mucking about while, if/else was too confusing. All I am trying to do is understand writing a function and calling it. I have read many tutorials and watch many videos and am still having trouble with this. All I want this code to do is print the area of a circle using the formula (a = PI * r * r). When I run the code it compiles fine. But is not calculating the area from user input. Which is "r". I feel like I am missing something small here. And if I could just wrap my mind around said small thing I am missing I would finally understand. So here is the modified code. Again this is just so I can get a better understanding of what I need to do to get the outcome I want.

Code:

#include <stdio.h>
#define PI 3.14


int area (int a, int r); //Function Call?

//Main Function right?
int main(void){
 
 float r, a;
 printf("The area of a circle with a radius of: ");
 scanf("%f", &r);
 printf("is %f\n", a);
return 0;
}


int area (int a, int r) //Function Definition?
{
a;
a = PI*r*r;
return ( a);
}

So the line you have marked as function call is ... well, not a function call. A function call would look like

Code:

a = area(4, 7)

note the values, not types of variables, in the parentheses. The thing you have marked is a function prototype, which tells the compiler what types of values go into the function and what type of value comes out.