数组基础常用方法

import java.util.Arrays;
import java.util.Random;

public class ArraysDemo {
    public static void main(String[] args) {
        int[] arr = new int[10];
        //将数组元素都设为9
        Arrays.fill(arr, 9);
        System.out.println("fill:" + Arrays.toString(arr));

        Random random = new Random();
        for (int i = 0; i < arr.length; i++) {
            //使用100以内的随机数赋值数组
            arr[i] = random.nextInt(101);
        }
        //重新赋值后的数组
        System.out.println("重新赋值:" + Arrays.toString(arr));

        //将索引为5的元素设为50
        arr[5] = 50;
        //排序
        Arrays.sort(arr);
        //排序后的数组
        System.out.println("sort排序后:" + Arrays.toString(arr));

        //查找50的位置
        int i = Arrays.binarySearch(arr, 50);
        System.out.println("值为50的元素索引:" + i);

        //复制一份新数组
        int[] newArr = Arrays.copyOf(arr, arr.length);
        System.out.println("copyOf后:" + Arrays.toString(newArr));
        
        //比较
        System.out.println("equals:" + Arrays.equals(arr, newArr));
    }
}

　　运行结果：

fill:[9, 9, 9, 9, 9, 9, 9, 9, 9, 9]
重新赋值:[35, 6, 43, 82, 96, 68, 76, 57, 89, 37]
sort排序后:[6, 35, 37, 43, 50, 57, 76, 82, 89, 96]
值为50的元素索引:4
copyOf后:[6, 35, 37, 43, 50, 57, 76, 82, 89, 96]
equals:true