定义一个int型的一维数组，包含10个元素，求出所有元素的最大值，最小值，平均值，和值

 import  java .util.Scanner;

public class TestArray {

public  static   void  main(String[] args) {
//int arr[] = new int[] {14,75,84,0,-54,-72,55,55,73,90};

Scanner s = new Scanner(System.in);
int arr[] = new int[10];
for(int i = 0; i < arr.length; i++) {
int n = i+1;
System.out.print("请输入第"+ n + "个数:");
arr[i] = s.nextInt();
}

for(int i = 0; i < arr.length; i++) {
System.out.print(arr[i] + " ");
}
System.out.println();

int max = arr[0];//最大值
int min = arr[0];//最小值
for(int i = 0; i < arr.length; i++) {
if(max < arr[i]) {
max = arr[i];
}
if(min > arr[i]) {
min = arr[i];
}
}
System.out.println("最大值为："+max);
System.out.println("最小值为："+min);

int sum = 0;//总和
float avg = 0;//平均值
for(int i = 0; i < arr.length; i++) {
sum += arr[i];
}
avg = (float)sum / arr.length;

System.out.println("总和为："+sum);
System.out.println("平均值为："+avg);

}

}

  

数组的复制、反转

 public class TestArray2 {

public static void main(String[] args) {
int arr[] = new int[] {1,2,3,4,5,6,7,8,9};
System.out.println("原数组为：");
for(int i = 0; i < arr.length; i++) {
System.out.print(arr[i] + " ");
}
System.out.println();

int arr1[] = new int[arr.length];
//复制
for(int i = 0; i < arr.length; i++) {
arr1[i] = arr[i];
}
System.out.println("复制数组为：");
for(int i = 0; i < arr1.length; i++) {
System.out.print(arr1[i] + " ");
}
System.out.println();

//反转
for(int x = 0, y = arr.length - 1; x < y; x++, y--) {
int temp = arr[x];
arr[x] = arr[y];
arr[y] = temp;
}
System.out.println("反转后为：");
for(int i = 0; i < arr.length; i++) {
System.out.print(arr[i] + " ");
}

}

}

  

结果

 原数组为：
1 2 3 4 5 6 7 8 9 
复制数组为：
1 2 3 4 5 6 7 8 9 
反转后为：
9 8 7 6 5 4 3 2 1