Java中的传值与传引用实现过程解析

public static void changeInt(int i) {// 改变int型变量的函数
    i = 100;
  }

  public static void changeString(String s) {// 改变String型变量的函数
    s = "changeString";
  }

  public static void changeModel(Model model) {// 改变Model型变量的函数
    model = new Model();
    model.i = 1;
    model.s = "changeModel";
  }

  public static void changeModel2(Model model) {// 改变Model型变量的成员的函数
    model.i = 1;
    model.s = "changeModel";
  }

  // 类Model

  class Model {
    public int i = 0;
    public String s = "no value";
  }

  // 测试程序
  public static void main(String[] args) {
    int i = 0;
    String s = "hello";
    Model model = new Model();
    Model model2 = new Model();

    changeInt(i);
    System.out.println("i=" + i);
    changeString(s);
    System.out.println("s=" + s);
    changeModel(model);
    System.out.println("model:" + model.s);
    changeModel2(model2);
    System.out.println("model2:" + model2.s);

  }

  i=0
  s=hello
  model:no value
  model2:changeModel