java类内实例化对象后会保存其内容

package j12;
import java.util.*;
 
 
class A{
    static int x[]=new int[100];
    static void ins(int location, int value){
        x[location]=value;
    }
}
 
class B{
    A a= new A();
    void xb(int location,int value){
        a.x[location]=value;
    }
    int  pb(int location){
        return a.x[location];
    }
}
 
public class j13 {
    public static void main(String args[]) {
        B b= new B();
        b.xb(0,1);
        b.xb(1,2);
        System.out.println(b.pb(0));    //1
        System.out.println(b.pb(1));    //2
        System.out.println(b.pb(2));    //3
    }
}