1. 数组的引用传递

public class TestArray {

    public  static void  changeAry1(int[] ary){

        int[] ary1 = {9,9,9};

        ary = ary1;

    }

    public  static void  changeAry2(int[] ary){

        ary[0] = 100;

    }

    public static void main(String[] args) {

        int[] ary = {1,2,3};

        System.out.println(Arrays.toString(ary));

        changeAry1(ary);

        System.out.println(Arrays.toString(ary));

        changeAry2(ary);

        System.out.println(Arrays.toString(ary));

    }

}

2. 对象的引用传递

public class TestObject {

    public static void change1(Person p){

        p = new TestObject().new Person();

        p.age= 100;

        p.name = "Lily";

    }

    public static void change2(Person p){

        Person pNew = new TestObject().new Person();

        pNew.age= 200;

        pNew.name = "Mary";

        p = pNew;

    }

    public static void change3(Person p){

        p.age= 200;

        p.name = "Tomy";

    }

    public static void main(String[] args) {

        Person p = new TestObject().new Person();

        p.age = 50;

        p.name="John";

        change1(p);

        System.out.println(p);

        change2(p);

        System.out.println(p);

        change3(p);

        System.out.println(p);

    }

    class Person{

        private int age;

        private String name;

        public String toString(){

            return this.age+","+this.name;

        }

    }

}

3. 再写一个jdk自带类的引用传递

public class TestOtherObject {

    public static void change1(List list){

        list = null;

    }

    public static void change2(List list){

        list.add(null);

    }

    public static void main(String[] args) {

        List list = new ArrayList();

        change1(list);

        System.out.println(list.size());

        change2(list);

        System.out.println(list.size());

    }

}

4. 字符串也是引用类型，也是引用传递

public class TestString {

    public static void changeStr1(String str){

        String newValue = "changeValue";

        str = newValue;

        // 或者直接str = "changeValue"; 也是一样

    }

    public static String changeStr2(String str){

        str = "changeValue";

        return str;

    }

    public static void main(String[] args) {

        String str = "hello";

        System.out.println(str);

        changeStr1(str);

        System.out.println(str);

        str = changeStr2(str);

        System.out.println(str);

    }

}