• 数组元素反转(就是把元素对调)
• 数组反转

class Demo10_Array {
 
    public static void main(String[] args) {
 
        int[] arr = {11,22,33,44,55};
 
        reverseArray(arr);
 
        print(arr);
 
    }
 
    /*
    数组元素反转
    1,明确返回值类型void
    2,明确参数列表int[] arr
    */
 
    public static void reverseArray(int[] arr) {
 
        for (int i = 0;i < arr.length / 2 ; i++) {
 
            //arr[0]和arr[arr.length-1-0]交换
 
            //arr[1]和arr[arr.length-1-1]交换
 
            //arr[2]和arr[arr.lentth-1-2]
 
            //...
 
            int temp = arr[i];
 
            arr[i] = arr[arr.length-1-i];
 
            arr[arr.length-1-i] = temp;
 
        }
 
    }
 
    /*
    数组遍历
    1,明确返回值类型void
    2,明确参数列表int[] arr
    */
 
    public static void print(int[] arr) {
 
        for (int i = 0;i < arr.length ;i++ ) {                //遍历数组中的每一个元素
 
            System.out.print(arr[i] + " ");                    //打印在控制台
 
        }
 
    }
 
}

• 数组冒泡排序

• 从小到大排序

  public class Sb {
  
    public static void main(String[] args) {
        int arr[]= {33,55,22,11,44};
        for(int i=0;i<arr.length-1;i++) {
            for (int j = 0; j < arr.length-1-i; j++) {
                if(arr[j]>arr[j+1]) {
                int temp=arr[j];
                arr[j]=arr[j+1];
                arr[j+1]=temp;
                }
            }
        }
        for(int x:arr) {
            System.out.print(x+" ");
        }
    }
  }