数组array

数组array

数组的结构: 数据类型[] 变量名 = 赋值;

数组的三种声明方式

    String[] array = { "U", "W", "H" };// 直接赋值

    String[] array2 = new String[4];// 定义长度

    // 通过new的方式赋值

    String[] array3 = new String[] { "A", "B", "C" };

实例

package fourcircle;

public class TwoDimensionArray {

    public static void main(String[] args) {

       int[][] arr = new int[3][5];

       // for循环遍历二维数组

       for (int i = 0; i < arr.length; i++) {

           for (int j = 0; j < arr[i].length; j++) {

               int element = (int) (Math.random() * 10);// 强制类型转换,随机产生[0,10)之间的整数

               arr[i][j] = element;

               System.out.print(arr[i][j]+"\t");

           }

           System.out.println();

       }

        System.out.println("--------------------华丽丽滴分割线-------------------------");

       // foreach

       for (int[] i : arr) {

           for (int j : i) {

               int a = (int) (Math.random() * 20);

               System.out.print(a + "\t");

           }

           System.out.println();

       }

        System.out.println("--------------------华丽丽滴分割线-------------------------");

       /* while遍历二维数组 */

       int i = 0;

       while (i < arr.length) {

           int j = 0;

           while (j < arr[i].length) {

               int a = (int) (Math.random() * 17);

               arr[i][j] = a;

               System.out.print(arr[i][j] + "\t");

               j++;

           }

           i++;

           System.out.println();

       }

        System.out.println("--------------------华丽丽滴分割线-------------------------");

       /* do-while遍历二维数组 */

       int j = 0;

       do {

           int k = 0;

           do {

               arr[j][k] = (int) (Math.random() * 37);

               System.out.print(arr[j][k] + "\t");

               k++;

           } while (k < arr[j].length);

           System.out.println();

           j++;

       } while (j < arr.length);

    }

}