Java练习——数组练习

lkbhua莱克瓦242025-11-15 14:58

一、求最值

java 复制代码

public class Test1 {
    public static void main(String[] args) {
        int[] arr = {33,5,22,44,55};
        int max = arr[0];
        for (int i = 0; i < arr.length; i++) {
            if (max < arr[i]){
                max = arr[i];
            }
        }
        System.out.println(max);
    }
}

二、遍历数组求和

java 复制代码

import java.util.Random;

public class Test2 {
    public static void main(String[] args) {
        Random r = new Random();
        int[] arr = new int[10];
        int sum = 0;
        int max = 0;
        for(int i = 0; i < arr.length; i++){
            arr[i] = r.nextInt(10);
        }
        for(int i = 0; i < arr.length; i++){
            System.out.print(arr[i] + " ");
        }
        System.out.println();
        System.out.println("------------------");
        for(int i = 0; i < arr.length; i++){
            sum += arr[i];
            if(arr[i] > arr[0]){
                max = arr[i];
            }
        }

        int avg = sum/arr.length;
        for(int i = 0; i < arr.length; i++){
            if(arr[i] < avg){
                System.out.println("小于平均数的元素为：" + arr[i]);
            }
        }
        System.out.println("和为：" + sum);
        System.out.println("平均数为：" + sum/arr.length);
        System.out.println("最大值为：" + arr[0]);

    }
}

三、交换数据

java 复制代码

public class Test3 {
    public static void main(String[] args) {
        int[] arr = { 1, 2, 3, 4, 5 };
        int temp = arr[0];
        for(int i = 0,j = arr.length - 1;i<j;i++,j--){
            temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
        }
        for (int i = 0; i < arr.length; i++) {
            System.out.println(arr[i]);
        }
    }
}

四、打乱数据

java 复制代码

import java.util.Random;

public class Test4 {
    public static void main(String[] args) {
        int[] arr = { 1, 2, 3, 4, 5 };
        Random r = new Random();
        for (int i = 0; i < arr.length; i++){
            int randomindex = r.nextInt(arr.length);
            int temp = arr[i];
            arr[i] = arr[randomindex];
            arr[randomindex] = temp;
        }

    }
}

课程学习来源于-B站@itheima！