Function Crisis!

[atticusr5]

hey everyone im new to this site so forgive any wrong-doing. Heres my problem, in my class we have just started learning about functions, so for an assignment I had to rewrite a program by converting any formulas into functions and calling the functions in main. im having issues with my sum function. I complied it first to test like this:

double Add(double a) //function definition
{
static double c=0;

c=a+c;

return c;
}

it adds up 1-10 and works wonderfully in a while loop (while(!infile.eof()). the loop reads data from infile>>number; and it works fine.

the problem is when i use this to find the sum later on my numbers are bloated. here is the part of the code in my project:

tempmax=0;
tempmin=0;
count=0;
bigie=-100; //Because the high value will be above -100 for this area
smalie=1000; //Because the temperature on earth is always belowe 1000

infile>>tmax>>tmin;

while(!infile.eof())
{
loophilow(infile,tmax,tmin,bigie,smalie);
tempmax=sum(tmax); //call the sum function for max temp
tempmin=sum(tmin); //call the sum function for min temp
maxavg=avg(tempmax,count);
minavg=avg(tempmin,count);
count++;
infile>>tmax>>tmin;
}

AND THE FUNCTION;

double sum(double a)
{
static double c=0;

c=a+c;

return c;
}

so basically I call the function 'sum' in my loop but im not getting the right sums. my averages and everything else is working fine but not the sum!

any ideas?

thanks, devang

[Bazzy]

As 'c' is static, its value will continuously grow.
Pass it by reference instead:

double sum(double a, double &c)
{
   c=a+c; // you can write this c+=a
   return c;
}

sum(tmax,tempmax);

[atticusr5]

thanks for the quick response

i just had a DUH moment reading that

thanks again.