Java 使用工具加入建構值

滑數右鍵出現

source Generate Getters and Setters 就會自動建好了

Java 帶入無限個參數的fuction

public class MethodParameter {

 /**
  * @param args
  */
 public static void main(String[] args) {
  System.out.println(getString(10,20));
  System.out.println(getString(10,20,"Hello"));
  System.out.println(getString(10,20,"Hello","World"));
  String [] sa = {"Hello","World"};
  System.out.println(getString(10,20,sa));
 }
 
        //...c帶入 string
 static String getString(int a,int b,String ...c){
  String toReturn = ""+a+","+b;
  for(String s : c)
   toReturn+=","+s;
  return toReturn;
 }

}

Java 算幾分鐘後的Class

 
public class MyTime {
 //final 靜態常數不會修改的
 public static final int HOURS_PER_DAY = 24;
 public static final int MINUTES_PER_HOUR = 60;
 
 private int mHour;
 private int mMinute;



public void setMytime(int inHour, int inMinute) {
  if( inHour < 0 && inHour >= HOURS_PER_DAY)
   return;
  
  if(inMinute < 0  && inMinute >= HOURS_PER_DAY)
   return;
  
  mHour = inHour;
  mMinute = inMinute;
 }


 public void passMinute(int inMinute) {  
  // (原本小時 + (分+傳入的分)/24小時的餘數)/24小時的餘數
  mHour = (mHour + (mMinute + inMinute) / MINUTES_PER_HOUR)
    % HOURS_PER_DAY;
  
  //(分+傳入的分)/60分的餘數
  mMinute = (mMinute + inMinute)%MINUTES_PER_HOUR;
 }


 public String toString() {  
  return (mHour >= 10 ? "": "0" )+ mHour + ":" + (mMinute >= 10 ? "" : "0") + mMinute;
 }

}

//呼叫方式

 
  MyTime mTime = new MyTime();
  mTime.setMytime(6, 30);
  System.out.println(mTime);
  mTime.setMytime(8, 50);
  System.out.println(mTime);
  mTime.passMinute(120);
  System.out.println(mTime.toString()); 
  

Java switch

int key = 71;
  switch (key) {
  case 1:
   System.out.println("等級1");
   break;
  case 2:
   System.out.println("等級2");
   break;
  case 3:
   System.out.println("等級3");
   break;
  case 4:
   System.out.println("等級4");
   break;
  case 5:
   System.out.println("等級5");
   break;
  default:
   System.out.println("等級不在範圍內");
   break;
  }
  

Java froeach

 
//對每個陣列v1 在a裡面
  for(int[] v1 : a){
   //對每個整立v 在v1裡面
   for(int v : v1){
    System.out.print(v +","); 
   }
  } 


for(型態：陣列){
}