5.数组的使用,最值和反转

 1 package com.duan.array;
 2 
 3 public class ArrayDemo03 {
 4     public static void main(String[] args) {
 5         int[] arrays = {1, 2, 3, 4, 5};
 6 
 7         //打印全部的数组元素
 8         for (int i = 0; i < arrays.length; i++) {
 9             System.out.println(arrays[i]);
10         }
11         System.out.println("=================");
12         //计算所有元素的和
13         int sum = 0;
14         for (int i = 0; i < arrays.length; i++) {
15             sum += arrays[i];
16         }
17         System.out.println("sum=" + sum);
18         System.out.println("==================");
19         //查找最大元素
20         int max = arrays[0];
21         for (int i = 1; i < arrays.length; i++) {
22             if (arrays[i] > max) {
23                 max = arrays[i];
24             }
25         }
26         System.out.println("max=" + max);
27     }
28 }
29 结果：
30 1
31 2
32 3
33 4
34 5
35 =================
36 sum=15
37 ==================
38 max=5

 1 package com.duan.array;
 2 
 3 public class ArrayDemo04 {
 4     public static void main(String[] args) {
 5         int[] arrays = {1, 2, 3, 4, 5};
 6         //for (int array : arrays) {
 7         //    System.out.println(array);
 8         //}
 9 
10         printArray(arrays);
11         int[] reverse = reverse(arrays);
12         System.out.println();
13         printArray(reverse);
14     }
15 
16     //打印数组元素
17     public static void printArray(int[] arrays) {
18         for (int i = 0; i < arrays.length; i++) {
19             System.out.print(arrays[i] + " ");
20         }
21     }
22 
23     //反转数组
24     public static int[] reverse(int[] arrays) {
25         int[] result = new int[arrays.length];
26 
27         //反转的操作
28         for (int i = 0, j = result.length - 1; i < arrays.length; i++, j--) {
29             result[j] = arrays[i];
30         }
31 
32         return result;
33     }
34 }
35 结果：
36 1 2 3 4 5 
37 5 4 3 2 1