数组的使用

普通的For循环

 package com.wu.array;
 ​
 public class ArrayDemo03 {
     public static void main(String[] args) {
 ​
         int[] arrays = {1,2,3,4,5};
 ​
         //打印全部的数组元素
         for (int i = 0; i < arrays.length; i++) {
             System.out.println(arrays[i]);
         }
 ​
         //计算所有元素的和
         int sum = 0;
         for (int i = 0; i < arrays.length; i++) {
             sum = sum + arrays[i];
         }
         System.out.println("和为:"+sum);
 ​
         //查找最大元素
         int max = arrays[0];
         for (int i = 0; i < arrays.length; i++) {
             if (max<arrays[i]){
                 max = arrays[i];
             }
         }
         System.out.println("最大值为:"+max);
     }
 }

For-Each循环

 //JDK1.5   没有下标
 for (int array : arrays) {
     System.out.println(array);
 }

数组作方法入参

数组作返回值

 package com.wu.array;
 ​
 public class ArrayDemo04 {
     public static void main(String[] args) {
         int[] arrays = {1,2,3,4,5};
 ​
         printArray(arrays);
         int[] reverse = reverse(arrays);
         System.out.println("\n"+"================");
         printArray(reverse);
     }
 ​
     //打印数组元素
     public static void printArray(int[] arrays){
         for (int i = 0; i < arrays.length; i++) {
             System.out.print(arrays[i]+" ");
         }
     }
     //反转数组
     public static int[] reverse(int[] arrays){
         int[] result = new int[arrays.length];
 ​
         //反转的操作
         for (int i = 0,j = result.length-1; i < arrays.length; i++,j--) {
             result[j] = arrays[i];
         }
         return result;
     }
 }