Quick question! I apologize to have to bother everyone again, but this is
really throwing me off!
Alright this function works, except I'm running into a problem with the
string being returned. It adds the 2 strings together and writes out the
correct number, however when I move back and forth between forms, the answer
sometimes changes each time the function is called again.
Example:
(correct answer to addition: 130.704)
First time form is loaded: 130.704
Second time form is loaded: 130.70404 (It seems the string is sometimes not
putting a nul at it's end???)
Third time loaded 130.704
Forth time loaded 130.704
Fifth time loaded 130.7040404
*Generally the number output is correct, yet it seems to be written wrong.*
Now in the below function I've selected the part that I believe is the
trouble zone. I believe it has to do with the string memory allocation.
Does anyone see anything wrong?
/***********************************************************************
*
* FUNCTION: AddDecimals()
*
* DESCRIPTION: This routine adds 2 Strings together
*
* PARAMETERS: - str1
* - str2
* - places
*
* RETURNED: CharPtr
*
***********************************************************************/
CharPtr AddDecimals(CharPtr str1, CharPtr str2, UInt places)
{
// Need to integrate limited decimal places in string
// Rounding as well...
decNum dec1; // Decimal structures
decNum dec2;
CharPtr lstr; // Strings
CharPtr strResult;
long int result; // Addition result
long int temp; // used to find length of result
int counter = 1; // Length of int
int x, i = 0, j = 0; // Counters
Boolean cont = true;
// Get Decimal structure from Strings
GetDecFromString(str1, &dec1);
GetDecFromString(str2, &dec2);
// Make numbers same length
if(dec1.dec > dec2.dec)
for(x = 0; x < (dec1.dec - dec2.dec); ++x)
dec2.num = dec2.num * 10;
else if(dec1.dec < dec2.dec)
for(x = 0; x < (dec2.dec - dec1.dec); ++x)
dec1.num = dec1.num * 10;
// Get the sum
result = dec1.num + dec2.num;
// Count # of places it occupies
for(temp = result; temp > 0; temp = temp / 10)
counter++;
/*******************************************/
// Allocate memory for local string
// lstr = (CharPtr)MemPtrNew(counter);
// strResult = (CharPtr)MemPtrNew(counter + 1);
/*******************************************/
/* I've tried hardcoding this (below) and it seems more solid that my first
dynamic approach (above) */
/* The first way (above) tends to show memory, and tends to lead to a
DmWriteCheck error now and then. */
/* Below just repeats the last few numbers of an answer when I call the
function the 2nd, 3rd, etc. times. Not finding the current nul? I don't
know! */
/*******************************************/
// Allocate memory for local string
lstr = (CharPtr)MemPtrNew(20);
strResult = (CharPtr)MemPtrNew(21);
/*******************************************/
// Covert UInt to String
StrIToA(lstr, result);
// Subtract length result by largest dec value
if(dec1.dec > dec2.dec)
counter = counter - dec1.dec;
else if(dec1.dec < dec2.dec)
counter = counter - dec2.dec;
// Copy String and insert decimal
while(lstr[i] != '\0')
{
if((i == (counter - 1)) && (cont == true))
{
strResult[j] = '.';
j++;
cont = false;
}
else
{
strResult[j] = lstr[i];
i++;
j++;
}
}
// Free memory
MemPtrFree(lstr);
MemPtrFree(strResult);
return(strResult);
}
Tim Astle
--
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