java数组

package com.array.jun;

import java.util.Arrays;
import java.util.Scanner;

public class ArrayTest {

    public static int[] arrayname0;            //定义数组
    public static int[] arrayname1 = {0,0,0,0,0};
    public static int[] arrayname2 = new int[]{1,2,3,4,5,6};    //静态数组初始化
    public static int[] arrayname3 = new int[10];                //动态数组初始化
    
    public static void arrayTest1(){
        for (int i : arrayname1) {
            System.out.print(arrayname1[i] + " ");    //foreach遍历第一个静态初始化数组没问题，第二种会抛出数组越界异常
        }
        System.out.println();
        for (int i = 0; i < arrayname2.length; i++) {
            System.out.print(arrayname2[i] + " ");    //for遍历都没问题
        }
        System.out.println("\n" + arrayname2[1]);
    }
    
    public static void arrayTest2() {        //测试数组静态工具类方法
        System.out.println(Arrays.binarySearch(arrayname2, 3));
        System.out.println(Arrays.binarySearch(arrayname2, 2, 4, 3));    //按值索引    binarySearch(a, fromIndex, toIndex, key)
        int[] array_b = Arrays.copyOf(arrayname2, 4);
//        int[] array_b = Arrays.copyOfRange(arrayname2, 2, 5);            //数组元素复制
        System.out.println(Arrays.toString(array_b));                    //tostring
        System.out.println(Arrays.equals(array_b, arrayname1));         //equals比较相等
        Arrays.fill(arrayname3, 4);                                        //填充
        System.out.println(Arrays.toString(arrayname3));
        Arrays.sort(arrayname2);                                        //排序
    }
    
    public static void test(){                        //测试方法，方便回调
        Scanner scan = new Scanner(System.in);
        switch (scan.nextInt()) {
        case 0:
            arrayTest1();
            break;
        case 1:
            arrayTest2();
            break;
        default:
            {
                System.out.println("请重新输入！");
                test();
            }
            break;
        }
    }
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        test();
    }

}

 案例：

package com.array.jun;

import java.util.Scanner;
/**
 * 
 * @author pengjun
 * @version 1.0
 * 完成一个数字金额转换成人民币读法的工具！
 */
public class SwitchTools {

    private static String[] hanzi = {"零","壹","贰","叁","肆","伍","陆","柒","捌","玖"};
    private static String[] unit = {"十","佰","千","万"};
    
    /**
     * @param num 需要被分解的浮点数
     * @param zheng 整数部分
     * @param xiao 小数部分
     * @return 返回一个含整数和小数字符串数组
     */
    public static String[] getNum(double num){
        long zheng = (long)num;
        long xiao = (long)Math.round((num - zheng) * 100);
        return new String[]{zheng + "",String.valueOf(xiao)};
    }
    
    /**
     * @param stringNum 被分解的字符串数组
     * @param numLen0 整数长度
     * @param numLen1 小数长度
     * @return result 拼接字符串
     */
    public static String readNum(String[] stringNum){
        String result = "";
        int numLen0 = stringNum[0].length();
        for (int i = 0; i < numLen0; i++) {
            int num0 = stringNum[0].charAt(i) - 48;
            if (i != numLen0 - 1 && num0 != 0) {
                result += hanzi[num0] + unit[numLen0 - i - 2];
            } else {
                result +=hanzi[num0];
            }
        }
        
        result += "点";
        int numLen1 = stringNum[1].length();
        for (int j = 0; j < numLen1; j++) {
            int num1 = stringNum[1].charAt(j) - 48;
            result +=hanzi[num1];
        }
        
        return result;
    }
    
    public static void test(){
        Scanner scan = new Scanner(System.in);
        double num = scan.nextDouble();
        System.out.println(readNum(getNum(num)));
    }
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        test();
    }

}