package lhy.core.util;import java.util.Arrays;import java.util.List;public class ArraysTest {    public static void main(String[] args) {                        int[] aa = {2,1,3,15,12,6};                 //1,数组转换成字符串:toString(int[] a)         System.out.println(Arrays.toString(aa));//[1, 2, 3, 4, 5, 6]                                //2,复制指定的数组，截取或用 0 填充 copyOf(float[] original,int newLength)        double[] dd = {4.1,6.2,3.4,9.6,8.8};        double[] ddCopy = Arrays.copyOf(dd, 7);        for (double d : ddCopy) {            System.out.print(d + "  "); //4.1  6.2  3.4  9.6  8.8  0.0  0.0          }                System.out.println("\n复制数组指定范围到新数组：");        //将指定数组的指定范围复制到一个新数组。        int[] aaCopy = Arrays.copyOfRange(aa, 0, 3);        for (int i : aaCopy) {            System.out.print(i + "  ");//2  1  3          }                                System.out.println("\n数组转list：");        //3,数组转list        String[] str = {"tom","jack","mashibing"};        List<String> list = Arrays.asList(str);        for (String string : list) {            System.out.println(string);        }                        System.out.println("快速排序sort:");        //4,数组排序sort：快速排序        Arrays.sort(aa);        for (int a : aa) {            System.out.print(a + "  "); //1  2  3  6  12  15          }        System.out.println("\n只排序数组指定下标部分：");        //对指定下标部分 排序        Arrays.sort(dd, 2, 4);        for (double d : dd) {            System.out.print(d +"  ");        }                                System.out.println("\nbinarySearch二分查找：");        //5：二分查找，必须先排序        Arrays.sort(aa);        int key = Arrays.binarySearch(aa, 4);        if(key >= 0){//找到了key >= 0            System.out.println("查找结果，key："+key+"  值为："+aa[key]);        }else{            System.out.println("数组中未查找到4，key:"+key); //数组中未查找到4，key:-4        }        //二分查找数组指定范围：        key = Arrays.binarySearch(aa, 0, 3, 3);        if(key >= 0){//找到了key >= 0            System.out.println("查找结果，key："+key +" 值："+aa[key]); //查找结果，key：2 值：3        }                                System.out.println("\n替换数组的值：");        //6：替换数组的值        int[] arr = new int[5];        Arrays.fill(arr, 2);        for (int i : arr) {            System.out.print(i+"  "); //2  2  2  2  2         }        System.out.println("\n部分替换数组的值：");        Arrays.fill(arr, 1, 3, 5);        for (int i : arr) {            System.out.print(i + "  ");//2  5  5  2  2          }                                System.out.println("\n挨着比较2个数组值是否相等：");        //7：比较2个数组是否相等        int[] arr1 = {1,2,3,4};        int[] arr2 = {2,1,3,4};        System.out.println(Arrays.equals(arr1, arr2)); //false            }    }