JAVA中的参数按值传递与按引用传递

看着有点恼火，你说为毛JAVA不用C或C++一样的指针传递呢？

C#和JAVA都号称取消了指针，但用户在编程时，不一样面对和学C/C++一样的变量及变量指针地址的问题么？

代码分三个：

 1 public class TempTest{
 2     private void test1(int a) {
 3         a++;
 4         System.out.println("The char A in test1 method value is :" + a);
 5     }
 6
 7     public static void main(String[] args) {
 8         TempTest t = new TempTest();
 9         int a = 3;
10         t.test1(a);
11         System.out.println("The char A in main method value is :" + a);
12     }
13 }

 1 public class TempTest1 {
 2     private void test1(A a) {
 3         a.age = 20;
 4         System.out.println("The age in test1 method value is :" + a.age);
 5     }
 6
 7     public static void main(String[] args) {
 8         TempTest1 t = new TempTest1();
 9         A a = new A();
10         a.age = 10;
11         t.test1(a);
12         System.out.println("The age in main method value is :" + a.age);
13     }
14 }
15 class A {
16     public int age = 0;
17 }

 1 public class TempTest2 {
 2     private void test2(A a) {
 3         a = new A();
 4         a.age = 20;
 5         System.out.println("The age in test2 method value is :" + a.age);
 6     }
 7
 8     public static void main(String[] args) {
 9         TempTest2 t = new TempTest2();
10         A a = new A();
11         a.age = 10;
12         t.test2(a);
13         System.out.println("The age in main method value is :" + a.age);
14     }
15 }
16 class A {
17     public int age = 0;
18 }

结果分三段：