如何只替换CString中第一次出现的字符？

Question

I have a CString st= $/Abc/cda/($/dba/abc)/ . I want to replace only first occurrence of $ with c:\\ .

I have tried to replace as

st.Replace("$","c:\");

But it replaced all occurrence of $ .

Could you please suggest me any logic to only replace the first occurrence of character.

Answer 1

Since you are replacing a single character by three characters, you can use CString::Find() and then CString::Delete() and CString::Insert() , like

int nInx = st.Find('$');
if (nInx >= 0)
{    st.Delete(nInx, 1);
     st.Insert(nInx, _T("C:\\");
}

Answer 2

Use

find_first_of //returns the iterator to the first occurance of string

and then

replace //to replace the iterator pointing to the first occurance

Answer 3

You could use void SetAt( int nIndex, TCHAR ch ); to replace just one character. And then int FindOneOf( LPCTSTR lpszCharSet ) const; to find the first occurance of $.

Like this :

st.SetAt( st.FindOneOf( "$" ), "C:/");

Answer 4

Here is a function that encapsulates the accepted answer from Edward Clements:

int replaceFirstOf(CString& str, const LPCSTR pszOld, const LPCSTR pszNew)
{
    int found = str.Find(pszOld);
    if (found >= 0)
    {
        str.Delete(found, 1);
        str.Insert(found, pszNew);
    }   
    return found;
}