package javaapplication4;

class Point {
private int x;
private int y;
private int z;

public void p(){
System.out.println("("+getx()+","+gety()+","+getz()+")");

}
public void Po(int a,int b,int c){
return a*a+b*b+c*c;
}
public int getx(){
return x;
}
public void setx(int a){
x=a;
}
public int gety(){
return y;
}
public void sety(int b){
y=b;
}
public int getz(){
return z;
}
public void setz(int c){
z=c;
}
}

public class Main {
  public static void main(String[] args) {
      Point point =new Point();
      point.setx(1);
      point.sety(2);
      point.setz(3);
  
      point.p();
   System.out.print(point.Po(1,2,3));
}

}
 
 
 
po函数说错了   大哥告诉我那里错了

public void Po(int a,int b,int c){
return a*a+b*b+c*c;
}
有return，当然要指定个类型。所以改成
public int Po(int a,int b,int c){
return a*a+b*b+c*c;
}

哦   谢谢哦

方法的命名要规范些：第一个单词首字母小写，第二个单词首字母大写