Java 引用和赋值 传值与传引用

package test;



 public class Test {

     int value;



     public static void main(String args[]) {

         Test test = new Test();

         test.value = 1;

         Test test2 = new Test();

         test2 = test;

         test.value = 2;

         System.out.println(test.value);// 2

         System.out.println(test2.value);// 2

     }

 } 
















package test;


 public class Test2 {
     int value;


     public static void main(String args[]) {
         Test test = new Test();
         test.value = 1;
         int temp = test.value;
         test.value = 2;
         System.out.println(test.value);// 2
         System.out.println(temp);// 1
     }
 }



















package test;


 public class Test3 {
     int value;


     public static void main(String args[]) {
         Test test = new Test();
         test.value = 1;
         Test temp = new Test();
         temp.value = test.value;
         test.value = 2;
         System.out.println(test.value);// 2
         System.out.println(temp.value);// 1
     }
 }


















package test;


 public class Test4 {
     int value;


     public static void main(String args[]) {
         Test test = new Test();
         test.value = 1;
         int[] temp = new int[1];
         temp[0] = test.value;
         test.value = 2;
         System.out.println(test.value);// 2
         System.out.println(temp[0]);// 1
     }
 }

















package test;


 import java.util.ArrayList;
 import java.util.List;


 public class Test5 {
     public static void main(String args[]) {
         Test test = new Test();
         List list = new ArrayList();
         list.add(test);
         Test test2 = (Test) list.get(0);
         System.out.println(test);// 同下
         System.out.println(test2);// 同上
     }
 }

















package test;


 import java.util.ArrayList;
 import java.util.List;


 public class Test6 {
     int value;


     public static void main(String args[]) {
         Test test = new Test();
         test.value = 1;
         List list = new ArrayList();
         list.add(test);
         test.value = 2;
         Test test2 = (Test) list.get(0);
         System.out.println(test.value);// 2
         System.out.println(test2.value);// 2
     }
 }

















package test;


 import java.util.ArrayList;
 import java.util.List;


 public class Test7 {
     int value;


     public static void main(String args[]) {
         Test test = new Test();
         test.value = 1;
         List list = new ArrayList();
         list.add(test);
         test.value = 2;
         Test test2 = (Test) list.get(0);
         System.out.println(test.value);// 2
         System.out.println(test2.value);// 2
     }
 }

















package test;


 public class Test8 {
     int value;


     public static void main(String args[]) {
         Test8 test = new Test8();
         test.value = 1;
         Test8 test2 = test;
         test.value = 2;
         System.out.println(test.value);// 2
         System.out.println(test2.value);// 2
     }
 }
















package test;


 public class Test9 {
     int value;


     public void setInt(int parameter) {
         parameter = 10;
     }


     public void setObject(Test9 parameter) {
         parameter.value = 10;
     }


     public static void main(String args[]) {
         Test9 test = new Test9();
         test.value = 1;
         test.setInt(test.value);
         System.out.println(test.value);// 1
         
         Test9 test2 = new Test9();
         test2.value = 1;
         test2.setObject(test2);
         System.out.println(test2.value);// 10
     }
 }

















package test;


 public class Test10 {
     int value;


     public void setInt(int parameter) {
         parameter = 10;
     }


     public void set() {
         value = 10;
     }


     public void setObject(Test10 parameter) {
         parameter.value = 10;
     }


     public static void main(String args[]) {
         Test10 test = new Test10();
         test.value = 1;
         test.set();
         System.out.println(test.value);// 10


         Test10 test2 = new Test10();
         test2.value = 1;
         test.setObject(test2);//注意是test不是test2
         System.out.println(test2.value);// 10
     }
 }

















package test;


 public class Test11 {
     int value;


     public static void main(String args[]) {
         Test11[] test = new Test11[1];
         test[0] = new Test11();
         test[0].value = 1;
         System.out.println(test[0].value);// 1


         Test11 test2 = new Test11();
         test2.value = 2;
         test2 = test[0];
         test[0].value = 3;
         System.out.println(test2.value);// 3
         test2.value = 4;
         System.out.println(test[0].value);// 4
     }
 }