java繼承 初始化順序

package Study.Initialization;class Base{private String str1=init("str1");private String str2=init("str2");public static String str3=init("static str3");public Base(String str1,String str2){System.out.println("Run Construction Base");this.str1=str1;this.str2=str2;}protected static String init(String str){System.out.println(str);return str+" init";}}class Derived extends Base{    private String str4=init("str4");    public static String str5=init("static str5");    public Derived(String str1,String str2,String str4){    super(str1,str2);    System.out.println("Run Construction Derived");    this.str4=str4;    }}public class extendInitialization {public static void main(String[] args) {System.out.println("run extendInitialization.main()");Derived d=new Derived("construction str1","construction str2","construction str4"); System.out.println("----------------------------------------");Derived d2=new Derived("construction str11","construction str22","construction str44"); }}

運行結果:

run extendInitialization.main()
static str3
static str5
str1
str2
Run Construction Base
str4
Run Construction Derived
----------------------------------------
str1
str2
Run Construction Base
str4
Run Construction Derived
總結:
   Derived的初始化順序:
    1.按定義時的順序初始化基類的static成員
    2..按定義時的順序初始化擴充類的static成員
    (以上兩條是對第一次定義擴充類對象時運行)
    3.按定義時順序執行基類的指定初始化
    4.執行基類的建構函式 
    5 按定義時的順序執行擴充類的指定初始化
    6.行擴充類的建構函式