C / C++ / MFC

Haroon Sarwar wrote:

char test[] = "Hello";

Haroon Sarwar wrote:

char* test = "Hello";

Haroon Sarwar wrote:

char test[] = "Hello";

Haroon Sarwar wrote:

char* test = "Hello";

char test1[] = "Hello";
char * test2 = "Hello";

test1[2]='p'; //  (1) legal, you can change the value of an element of the array
// test1 = test2; (2) ILLEGAL, compiler error, test1 is a const pointer

//test2[2]='p';   (3) ILLEGAL, runtime error, you cannot change read-only memory area
test2 = test1;//  (4) legal, you can change the pointer value
test2[2]='p'; //  (5) legal, since now, test2 points to the same writable memory area of test1

Bravoone_2006 wrote:

How Can i get the result?(from Col3);

int nsum = 0;<br />
for( int nRow = 0; nRow < m_lis.GetItemCount();nRow++)<br />
{<br />
 for( int nColumn = 0; nColumn < 3;nColumn ++)<br />
   {<br />
     CString csText = GetItemText(nRow ,nColumn );<br />
     nsum += _atoi( csText);<br />
    }<br />
}

Bravoone_2006 wrote:

int nsum = 0;

Bravoone_2006 wrote:

m_sum.SetWindowText(csText);

int nsum = 0;
for( int nRow = 0; nRow < m_list1.GetItemCount();nRow++)
{
    for( int nColumn = 0; nColumn < 2;nColumn++)
    {
        CString csText = m_list1.GetItemText(nRow ,nColumn );
        nsum += atoi( csText);
        m_sum.SetWindowText(csText);
    }
}

int CMyDialogBox::SumColumn(CListCtrl* pList, int nColumn)
{
    // the first thing i'd do is make sure the specified column is within the 
    // range of available columns, but i'm goin g to leave that as an exercise 
    // for you
    
    // declare and initialize some vars
    int nSum = 0;
    int nRows = pList->GetItemCount();
    CString csText = "";
    // if we actually have rows to process
    if (nRows > 0)
    {
        // process each one
        for (int nRow = 0; nRow < nRows; nRow++)
        {
            // retrieve the text from the current row and specified column
            csText = pList->GetItemText(nRow ,nColumn );
            // if the string isn't empty
            if (!csText.IsEmpty())
            {
                // establish a string a valid characters so we can ensure 
                // that the extracted string is in fact a number
                CString sNumbers = "0123456789";
                // assume we have a valid integer value
                bool bIsValid = true;
                // check each character in the exttracted string
                for (int i = 0; i < csText.GetLength(); i++)
                {
                    // if we find the character in the validation string, 
                    // the number might be valid
                    bIsValid = (sNumbers.Find(csText.GetAt(i) < 0);
                    // if the exttracted string wasn't valid 
                    if (!bIsValid)
                    {
                        // get out of the loop
                        break;
                    }
                }
                // if the exttracted string WAS valid, add the value to nSum
                if (bIsValid)
                {
                    nSum += atoi( csText);
                }
            }
        }
    }
}

void CMyDialog::SomeFunction()
{
    // by the way, if you want to sum the second column, you need to 
    // specify 1 as the second paramter
    int nResult = SumColumn(&m_list1, 1);
    CString csText;

    // turn nSum into a string - we can use the csText string we've 
    // already been using
    csText.Format("%d", nSum);
    // put the csText string into the edit control
    m_sum.SetWindowText(csText);
}

John Simmons / outlaw programmer wrote:

NOTE: I didn't want to use the atoi function to determine the validity of the converted string because if it's not a number, it returns 0, which IS a number. It's also a VALID number, so you can't just assume that the return value is what you expect it to be. That's why I included code to check each character one at a time before trying to convert it to a numeric value.

DavidCrow wrote:

So why not just use strtol()?

Bravoone_2006 wrote:

m_sum.SetWindowText(csText);

int nsum = 0;<br />
for( int nRow = 0; nRow < m_list1.GetItemCount();nRow++)<br />
{<br />
for( int nColumn = 0; nColumn < 2;nColumn++)<br />
{<br />
CString csText = m_list1.GetItemText(nRow ,nColumn );<br />
nsum += atoi( csText);<br />
}<br />
}<br />
TCHAR tcsum[50]<br />
_itoa(   nsum,  tcsum, 10 );<br />
m_sum.SetWindowText(tcsum);