To achieve the following functions under VC ++

cherryfei

// Validate the input data
if (m_old.GetLength ()! = 8)
{
MessageBox ("Please enter 8 clear text", "Friendly Tips");
return;
}
This code is to verify whether the input data is 8 digits, or it will prompt to enter again. Now it is necessary to fill in 8 bits with 0 if the input data is less than 8 bits. How can prawns be realized? Please elaborate, I am a rookie just learning VC. I don't understand the format method.

andy_0023

if (m_old.GetLength () <8)
{
  for (int n = m_old.GetLength (); n <8; n ++)
    m_old + = '0';
}

cuoren1984

Upstairs is the last 0, the first 0 is as follows
if (m_old.GetLength () <8)
{
  CString str;
  for (int n = m_old.GetLength (); n <8; n ++)
      str + = '0';
    m_old + = str;
}

kvvvvlee

The upstairs is wrong, the first 0 should be
if(m_old.GetLength()<8)
{
  CString str;
  for(int n = m_old.GetLength();n<8;n++)
      str += '0';
    m_old = str+m_old;
}

ajsdhja

The above two, what is the difference between your code.

l4331530

m_old+=str; is equivalent to m_old=m_old+str; is 0
m_old = str+m_old; is the first 0