主题：程序代码——简单的打字测试程序

今天在机房上机，机房里的JBuilder里面的光标与字符不对应让我不能得心应手地写程序，只能写了一半就交上去了。现在我已经写完了。不知道好不好。现在拿出来希望和大家共享并探讨一下。

import javax.swing.JOptionPane;
public class hello
{
  public static void main(String args[]) {
    int j,cou=0;
    String r = "";
    String x,b,c;
    for (int i = 0; i < 10; ) {
      j = (int) (Math.random() * 200);
      if (j > 97 && j < 123) {
        i++;
        r = r + (char) (j);
      }
    }
    x = JOptionPane.showInputDialog(r);
    if (x.length() != 10) {
      JOptionPane.showMessageDialog(null, "字数不对！", "Result",
                                    JOptionPane.PLAIN_MESSAGE);
      System.exit(0);
    }
    else if (x.compareTo(r)==0) {
        JOptionPane.showMessageDialog(null, "完全匹配！谢谢合作！", "Result",
                                      JOptionPane.PLAIN_MESSAGE);
        System.exit(0);
      }
      else {
       for(int i=0;i<10;i++)
       {
        b=x.substring(i,i+1);
        c=r.substring(i,i+1);
        if(b.compareTo(c)!=0)
        ++cou;
       }
        JOptionPane.showMessageDialog(null, "你输入错了"+cou+"个字母", "Result",
                                      JOptionPane.PLAIN_MESSAGE);
        System.exit(0);
      }
    
  }
}