Thread: Passing Value back problem

My program asks the user to input sold and price. both are floting point number. they use the same function for validation. the function checks the input data which must be 0-9 and/or "."
i use "pass" for checking true or false. it is supposed to send the value of "pass" to the main but it isn't
how can i fix this problem?
Thanks

Code:

#include <stdio.h>
#include<string.h>
#include<stdlib.h>

void check(struct Sell s,char amoun[50]);
struct Sell 
{
	float amountsold,retailprice;
	bool pass;
};
//******************M a i n*************
	
 int main  (void)

{
struct Sell st;
bool k=true;
char amountsol[50],retailprice[50];
int e,len,i;
st.pass=true;
	do
	{
			
			
		do
		{
		    puts("Enter  amount sold: ");
		    gets(amountsol);
		    check(st,amountsol);
		    printf("Pass Main:%d\n",st.pass);
		}while(!st.pass);
	 st.amountsold=atof(amountsol);
	printf("Amoundsold :%f\n",st.amountsold);
		do
		{
		puts("Enter retailprice: ");
		gets(retailprice);
		check(st,retailprice);
		printf("Pass Main :%d\n",st.pass);
		}while(!st.pass);
	st.retailprice=atof(retailprice);
	} while(!st.pass);
	
	printf("Amountsold :%f \n",st.amountsold);
	printf("amountinFunct: %f\n",st.retailprice);
}
//**********f u n c t i o n ********************
void check(struct Sell s,char num[50])
{
			
int e,len,i,n;
len=strlen(num);
for (e=0;e<len;e++)
         {
	switch (num[e])
              {
					
	case '0' : 
                 	case '1' :
                 	case '2' :
                  	case '3' :
                  	case '4' :
                  	case '5' :
                    case '6' :
                  	case '7' :
                  	case '8' :
                  	case '9' :
                  	case '.' :
                  	s.pass=true;
                  	printf("Pass Funct:%d\n",s.pass);
                  	break;
                  	default : 
                    s.pass=false;
                    printf("Pass Funct:%d\n",s.pass);
                    puts(" Amount sold error \n");
           	break;
           	}
           }
    
           printf("Pass in Function before return :%d\n",s.pass);
return(s.pass);
}

if im not wrong, which i could well be, the problem is in your function declaration.

void function(params)

that means it wont pass anything back. wat u want is probably this:

bool function(params)

which indicates itll return a bool, or int as main does "int main(), etc.

im relatively new to c but i think this is right P

it doesn't seem to be working
any suggestion?
cheers

another thing u might try
since Check returns s.pass...it wont modify s.pass in the function that calls it.
this will:
s.pass = check....

as s.pass becomes the returned value

or

if(check(...))

etc.

Hammer
i tried it but nothing change :-(

Thanks Hammer
just woke up
i am quite new with C
i did what u told me except the last one
"- I also had to typedef an int to bool, and using #define's for true/false as my compiler doesn't recognise them. "
i don't know how to do it
the point of this program is when u put any character in to the number, for example 12.a ,2w,s, 150.y etc,it should show an error message and ask the same question for u to put the number again
thanks

thanks you guys
i solve this problem
actually it was my mistake i was just confused
Thanks