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){
________

你对照着看吧
4.import java.io.*;
class Variable{
int x=0,y=0,z=0;
void init(int x,int y)
{ int x=x; int y=y;
int z=5;
System.out.println(" in init ");
System.out.println("x="+ x +"y="+ y +"z="+ z);
}}
public class VariableTest{
public static void main(String args[]){
Variable v=new Variable();
System.out.println("before init");
System.out.println("x="+ x +"y="+ y +"z="+ z);
v.init(20,30);
System.out.println("after init");
System.out.println("x="+ x +"y="+ y +"z="+ 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){
point p =new point(10,20);

System.out.print("x="+p.x+" y="+p.y);
}