vc6.0环境，如何写if语句使数控M代码分成四类？

Question

 
void CS1Dlg::OnBtnYm() 
{
	// TODO: Add your control notification handler code here
	///////3///////////
	 CStdioFile file;
	   CString strLine;
	   CString strGCode;
	   	int n;//预处理用;
		int j=0;
		int g=0;
		int m=0;
	   file.Open(strFilePathName, CFile::modeRead | CFile::typeText);
       	while (1)
		{
			n=0;
		  if (file.ReadString(strLine) == NULL)  break; 
		  
		  strLine.Format("%s\n", strLine);
		  strLine.Remove(0x20); 	//去掉空格		  
		  while(strLine[n]!='\n')
			{
				  switch(strLine[n])
				  {
					 case 'N':
					 case 'n':
                      N[j]=ReadNum(n,strLine); 
						  break;
					 case 'G':
					 case 'g':
					  g=ReadNum(n,strLine);
		             case 'M':
					 case 'm':
					  m=ReadNum(n,strLine);

					 if(g>= 0  &&  g<= 3)
					 {
						Ga[j]=g;
					 }
					 else if(g>= 40  &&  g<= 42)
					 {
						Gd[j]=g;	
					 }else
					 {
						 if(m)
						 {
							 MI[j]=m;
						 }
						 else if(m==6
						 {
							 MC[j]=m;
							 else if(m=
					 }
						 break;
                     case 'X':
					 case 'x':
                      X[j]=ReadNum(n,strLine); 
						 break;
					 case 'Y': 
					 case 'y':
                      Y[j]=ReadNum(n,strLine);
						 break;
				     case 'I': 
					 case 'i':
                      I[j]=ReadNum(n,strLine);
						 break;
					 case 'J': 
					 case 'j':
                      J[j]=ReadNum(n,strLine);
						 break;

					 default:break;				  
				  }
				  n++;
			
			}
		  j++;
		}   
	  file.Close();   
}

怎么写if语句分类

Answer 1

把M03到M11定义对应常量，把同一类的用if 语句的或条件判断，其他类用多个else if 判断