Stumped - Functions - working with Doubles 1

[jamez05]

I've tried numerous ways to try to pass a double to a function and gets its value back with no success:

My main function declares the following variables and prototype for the function pkaden:

char ErrorMsg[150];
char s[MAX_SMI];
double PKA;
int pkaden(char *,char *,double);
char CF_PKA[150];

I want the function to return a 1 if no errors along with the an errorMsg or a PKA value. Here's the call in my main function. I'm using a Coldfusion API, so that's what the p-request is about:

CF_PKA[0] = '\0';
if (pkaden(s,ErrorMsg,PKA)) {
  sprintf(CF_PKA,"%f",PKA);
}
else {
  strcpy(CF_PKA,ErrorMsg);
}
pRequest->SetVariable("CF_PKA",CF_PKA);

in my pkaden function, I set PKA = 1000 for testing purposes. However, after I check it following the function call in my main page, it doesn't change value and is still set to -99.0

Can anyone help me? Not sure what I'm doing wrong.

 

[jamez05]

Sorry, there's an error in my above example. Where I declare PKA, it should read

double PKA = -99.0;

 

[uolj]

If you want a function to change the value of a parameter, you must pass the parameter by reference. The easiest way to do this is, well, to pass it by reference:

int pkaden(char *,char *,double &);