喜乐惠商城退货流程:还是请教高手帮忙java的！！

4. import java.io.*;
class Variable{
int x=0,y=0,z=0;
void init(int x,int y)
{______x=x;_____y=y;
int z=5;
System.out.println(" in init ");
System.out.println("x="+___+"y="+___+"z="+___);
}}
public class VariableTest{
public static void main(String args[]){
Variable v=new Variable();
System.out.println("before init");
System.out.println("x="+___+"y="+___+"z="+____);
v.init(20,30);
System.out.println("after init");
System.out.println("x="+____+"y="+____+"z="+____);
}
}
5.class point{
int x,y;

point(int a,int b){
x=a;y=b;
}
}
public class createPoint {
public static void main(String[] args){
_________=new point(10,20);

System.out.print("x="+p.x+" y="+p.y);
}
}
6.class Student{
static int num;
int number;

int add1( ){
num=num+1;
return num;
}

int add2( ){
number=number+1;
return number;
}
}

public class StuDemo{
public static void main(String args[ ]){
_______ zhang=new Student( );
_______ wang=new Student( );
_______ jiang=new Student( );
System.out.println("zhang.num="+zhang.add1( ));
System.out.println("zhang.number="+zhang.add2( ));
System.out.println("wang.num="+________);
System.out.println("wang.number="+wang.add2( ));
System.out.println("jiang.num="+jiang.add1( ));
System.out.println("jiang.number="+_________);
}
}
7.class RunDemo
{ private String userName,password;

RunDemo( )
{ System.out.println("All is null!");
}

RunDemo(String name)
{ userName=name;
}

RunDemo(______ name,_______ pwd)
{ this(name);//在构造函数内部使用this，它用于指代另外一个构造函数，但不能指代非构造函数
password=pwd;
check( );
}

void check( )
{ ______ s=null;
if(userName!=null)
s="userName:"+userName;
else
s="please input your password!";
if(password!="ThisWord")
s=s+" invaid!";
else
s=s+" password:********";
System.out.println(s);
}
}

public class Demo
{ public static void main(String args[ ])
{ new RunDemo( );
new RunDemo("Bill");
new RunDemo(null,"Bill");
new RunDemo("Bill","ThisWord");
}
}