public class BubbleSort {

    public static void main(String args[]) {
           int[] arr = {1,3,2,9,5,7,6,8,4};
        System.out.println("沒有排序之前的數組為:");
        for (int num : arr) {
            System.out.print(num+" ");
        }

        for (int i = 0; i <arr.length ; 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;
                }
            }
        }
        System.out.println();
        System.out.println("排序後的數組為:");
        for (int num : arr) {
            System.out.print(num+" ");
        }

        }

}

冒泡排序呀