面向对象之自定义数组工具类ArraysUtil

package day1_5;

import java.util.Arrays;

public class ArraysUtil {
    //遍历数组
    public void print(int[] arr) {
        for (int i : arr) {
            System.out.print(i + " ");
        }
        System.out.println();
    }

    //复制数组
    public int[] copy(int[] arr) {
        int[] newArr = new int[arr.length];
        for (int i = 0; i < arr.length; i++) {
            newArr[i] = arr[i];
        }
        return newArr;
    }

    //最大值
    public int getMax(int[] arr) {
        int maxValue = arr[0];
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] > maxValue) {
                maxValue = arr[i];
            }
        }
        return maxValue;
    }

    //最小值
    public int getMin(int[] arr){
        int minValue = arr[0];
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] < minValue) {
                minValue = arr[i];
            }
        }
        return minValue;
    }

    //求和
    public int getSum(int[] arr){
        int sumValue = 0;
        for (int i = 0; i < arr.length; i++) {
            sumValue += arr[i];
        }
        return sumValue;
    }

    //平均值
    public int getAvg(int[] arr){
        return getSum(arr)/arr.length;
    }


    //查找元素
    public int getIndex(int[] arr,int target){
        //线性查找
        for (int i=0; i < arr.length; i++) {
            if (arr[i] == target) {
                return i;
            }
        }
        return -1;//负数表示数组中没有目标元素
    }

    //反转数组
    public void reverse(int[] arr){
        for (int i = 0,j = arr.length-1; i < j; i++,j--) {
            int tmp = arr[i];
            arr[i] = arr[j];
            arr[j] = tmp;
        }
    }

    //冒泡排序
    public void sort(int[] arr){
        for (int i = 0; i < arr.length-1; i++) {
            for (int j = 0; j < arr.length-i-1; j++) {
                int tmp;
                if (arr[j] > arr[j + 1]) {
                    tmp = arr[j];
                    arr[j] = arr[j+1];
                    arr[j+1] = tmp;
                }
            }
        }
    }

}

测试类

package day1_5;


import java.util.Arrays;

public class ArrayUtilTest {
    public static void main(String[] args) {
        int[] arr = new int[]{12,46,-12,90,-46,0,4,-90,89};
        ArraysUtil arraysUtil = new ArraysUtil();
        System.out.println("----遍历数组----");
        arraysUtil.print(arr);
        System.out.println("----复制数组----");
        int[] arr2 = arraysUtil.copy(arr);
        System.out.println(Arrays.toString(arr2));
        System.out.println("----最大值----");
        int max = arraysUtil.getMax(arr);
        System.out.println(max);
        System.out.println("----最小值----");
        int min = arraysUtil.getMin(arr);
        System.out.println(min);
        System.out.println("----求和----");
        int sum = arraysUtil.getSum(arr);
        System.out.println(sum);
        System.out.println("----平均值----");
        int ave = arraysUtil.getAvg(arr);
        System.out.println(ave);
        System.out.println("----查找元素----");
        int index = arraysUtil.getIndex(arr, -12);
        System.out.println(index);
        System.out.println("----反转数组----");
        arraysUtil.reverse(arr);
        System.out.println(Arrays.toString(arr));
        System.out.println("----冒泡排序----");
        arraysUtil.sort(arr);
        System.out.println(Arrays.toString(arr));

    }
}

打印结果