學習筆記3

package cn.itcast.liukong;

public class TestThis {

 public void jump(){

  System.out.println("it's jumping now!");

 }

 public void run(){

  jump();

  this.jump();/*/d等效于裡面的代碼。this 關鍵字最大作用是讓類中一個方法，

  通路該類的另一個方法或屬性。*/

  TestThis dog = new TestThis();

  dog.jump();

  System.out.println("it's running now!!");

}

public class Testdog {

  public static void main(String[]args){

   TestThis Tdog=new TestThis();

   Tdog.run();

  }

public class TestStaticthis {

   new TestStaticthis().run();//從新建立一個對象來調用非靜态方法。靜态方法無法通路非靜态方法

   //run();

   /*Exception in thread "main" java.lang.Error: Unresolved compilation problem:

 Cannot make a static reference to the non-static method run() from the type TestStaticthis

靜态方法無法通路非靜态方法。this.run()

 at cn.itcast.liukong.TestStaticthis.main(TestStaticthis.java:5)*/

  public void run(){

   System.out.println("run!!");

public class TestRefenceTransfer {

 public static void swap(DataWrap dw){

  int tmp=dw.a;

  dw.a=dw.b;

  dw.b=tmp;

  System.out.println("swap方法中的a的屬性值是："+dw.a+";b的屬性值是："+dw.b);

  dw=null;

 public static void main(String[]args){

  DataWrap dw= new DataWrap();

  dw.a=6;

  dw.b=9;

  swap(dw);

  System.out.println("交換結束後，a屬性是"+dw.a+";b屬性的值是"+dw.b);

public class TestPrimitiveTransfer {

 public static void swap(int a ,int b){

  int tmp;

  tmp=a;

  a=b;

  b=tmp;

  System.out.println("a="+a+ ";b="+b);

 public static void  main(String[]args){

  int a=3;

  int b=90;

  swap(a,b);

  System.out.println("a="+a+";b="+b);

public class Resursive {

 public static int intf(int n){//此番方法需要有傳回值為×××，故 非void 而int

  if(n==0)

   return 1;

  else if (n==1)

   return 4;

  else

   return 2*intf(n-1)+intf(n-2);//遞歸；；；

  System.out.println(intf(3));

public class Person {

 public String name;

 public static int EyeNum;