程序代码：

class myClass
{
    private int x;
    private int y;
    private int z;
    /*****
    //system default
    //myClass my=new myClass();
    public myClass()
    {
        //do nothing
    }
    *****/
    //myClass my=new myClass();
    public myClass()
    {
        x=0;
        y=0;
        z=0;
    }
    //myClass my=new myClass(10);
    public myClass(int i)
    {
        x=i;
        y=x;
        z=x;
    }
    //myClass my=new myClass(10,11);
    public myClass(int i,int j)
    {
        x=i;
        y=j;
        z=y;
    }
    //myClass my=new myClass(1,2,3);
    public myClass(int i,int j,int k)
    {
        x=i;
        y=j;
        z=k;
    }
}