Arrays类详细讲解

package com.wuming.struct;

import java.util.Arrays;

public class Demo14 {
    public static void main(String[] args) {
        //Arrays数组类，操作数组：排序、搜索等
        int[] a={1,2,3,4,9090,31231,543,21,3,23};
        System.out.println("======System.out.println(a);=======1=======");
        System.out.println(a);
        //打印数组元素Arrays.toString
        System.out.println("============ System.out.println(Arrays.toString(a));=======2======");
        System.out.println(Arrays.toString(a));
        System.out.println("===========printArray(a);======3=======");
        printArray(a);
        //数组排序
        Arrays.sort(a);
        System.out.println("=======System.out.println(Arrays.toString(a));======4=====");
        System.out.println(Arrays.toString(a));
      
        Arrays.fill(a,2,4,0);//下标为2到4之间的用0填充，[2,4),就是下标为2,3的
        System.out.println("=======System.out.println(Arrays.toString(a));=====6======");
        System.out.println(Arrays.toString(a));
    }
    public static void printArray(int[] a) {
        for (int i = 0; i < a.length; i++) {
            if (i==0){
                System.out.print("[");
            }
            if (i==a.length-1){
                System.out.print(a[i]+"]");
            }else{
                System.out.print(a[i]+", ");
            }
        }
    }
}

======System.out.println(a);=======1=======
[I@4554617c
============ System.out.println(Arrays.toString(a));=======2======
[1, 2, 3, 4, 9090, 31231, 543, 21, 3, 23]
===========printArray(a);======3=======
[1, 2, 3, 4, 9090, 31231, 543, 21, 3, 23]=======System.out.println(Arrays.toString(a));======4=====
[1, 2, 3, 3, 4, 21, 23, 543, 9090, 31231]
=======System.out.println(Arrays.toString(a));=====6======
[1, 2, 0, 0, 4, 21, 23, 543, 9090, 31231]