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){


}