数组

1.      一维数组声明

Int a[];   int[] a;

声明时不能定义长度

Int[5] a;//错误

2.      一维数组的初始化

Int[] a = {1,2,3,4};

int[] a = new int[2];

a[0] = 1;a[1] = 2;

int[] a = new int[]{1,2,3};

3.      数组排序

Import java.util.Arrays;

Arrays.sort(数组名);

4.      扩展数组

Import java.util.Arrays;

Int[] a = {1,2,3};

Int[] b = Arrays.copyOf(a,5);

a = b;

5.      二维数组静态初始化

Int[][] a = {{1,2},{3,4,5},{6,7}};

6.      二维数组动态初始化

Int[][] a =new int[3][5];

Int[][] a = new int[3][];

a[0] =new int[2];

a[1] =new int[2];

a[2] =new int[3];