- 定义一个数组,存储1,2,3,4,5,6,7,8,9,10,遍历数组,统计数组里面一共有多少个能被3整除的数字
public class index {public static void main(String[] args) {int[] arr = {1,2,3,4,5,6,7,8,9,10};int count = 0;for (int i = 0; i < arr.length; i++) {if (arr[i] % 3 == 0){count++;//System.out.println(arr[i]);}}System.out.println("数组里面共有"+count+"个数字能被3整除");} }
- 定义一个数组,存储1,2,3,4,5,6,7,8,9,10,遍历数组,如果是奇数,将数字变为原来的两倍,如果是偶数则变为原来的二分之一
public class index {public static void main(String[] args) {int[] arr = {1,2,3,4,5,6,7,8,9,10};int count = 0;for (int i = 0; i < arr.length; i++) {if (arr[i] % 2 == 0){arr[i] /= 2;}else{arr[i] *= 2;}}for (int i = 0; i < arr.length; i++) {System.out.println(arr[i]);}} }
- 已知数组元素为{33,5,22,44,55},请找出数组中最大值和最小值并打印在控制台
public class index {public static void main(String[] args) {int[] arr = {33,5,22,44,55};//初始化值一定要是数组中的值int max = arr[0];int min = arr[0];for (int i = 1; i < arr.length; i++) {if (arr[i] > max){max = arr[i];}}for (int i = 1; i < arr.length; i++) {if (arr[i] < min){min = arr[i];}}System.out.println("数组中最大值为"+max);System.out.println("数组中最小值为"+min);} }
- 生成10个1~100之间的随机数存入数组,求所有数据的和,平均数,统计有多少个数据比平均值小
import java.util.Random; import java.util.Scanner; public class index {public static void main(String[] args) {int[] arr = new int[10];Random r = new Random();for (int i = 0; i < arr.length; i++) {int number = r.nextInt(100) + 1;arr[i] = number;}int sum = 0;int count = 0;for (int i = 0; i < arr.length; i++) {sum = sum + arr[i];}int avg = sum / arr.length;for (int i = 0; i < arr.length; i++) {if(arr[i] < avg){count++;}}System.out.println("数组中所有数据和为"+sum);System.out.println("数组平均值为"+avg);System.out.println("数组中小于平均值的数有"+count+"个");} }
- 定义一个数组,存入1,2,3,4,5,按照要求交换索引对应的元素,交换后:5,4,3,2,1
public class index {public static void main(String[] args) {int[] arr = {1,2,3,4,5};for(int i = 0,j = arr.length - 1;i < j;i++,j--){int temp = arr[i];arr[i] = arr[j];arr[j] = temp;}for (int i = 0; i < arr.length; i++) {System.out.print(arr[i] + " ");}} }
- 定义一个数组,存入1,2,3,4,5,要求打乱数组中所有数据的顺序
import java.util.Random; import java.util.Scanner; public class index {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;}for (int i = 0; i < arr.length; i++) {System.out.print(arr[i] + " ");}} }