java的数组(2)

数组的初始化

数组定义与为数组元素分配空间和赋值的操作分开进行

动态初始化

例如：

public class Test {public static void main(String[] args) {int a[];a = new int[3];a[0] = 3 ; a[1] = 9 ; a[2] = 8 ;Date days [];days = new Date[3];days[0] = new Date(1,12,2012);days[1] = new Date(2,12,2012);days[2] = new Date(3,12,2012);}}class Date {int year; int month; int day;Date(int y ,int m , int d) {year = y;month = m;day = d;}}

静态初始化：

在定义数组的同时就为数组元素分配空间并赋值

例如：

public class Test {public static void main(String[] args) {int a[] = {1 , 3 , 5};Date days[] = {new Date(1,12,2012),new Date(2,12,2012),new Date(3,12,2012)};}}       class Date {   int year,month,day;       Date(int y, int m , int d) {   year = y;   month = m;   day = d;}}

数组是引用类型，它的元素相当于类的成员变量，因此数组分配空间后，每个元素也被按照成员变量的规则被隐式初始化

例如： 

public class Test {public static void main(String[] args) {int a[] = new int[5];Date[] days = new Date[3];System.out.println(a[3]);System.out.println(days[2]);}}class Date {int year,month,days;    Date(int y,int m,int d){year = y;month = m;days = d;}}