# Java 程序：升序和降序的冒泡排序 > 原文： [https://beginnersbook.com/2014/07/java-program-for-bubble-sort-in-ascending-descending-order/](https://beginnersbook.com/2014/07/java-program-for-bubble-sort-in-ascending-descending-order/) 在本教程中，我們將看到如何在按升序和降序進行排序。使用[冒泡排序](https://en.wikipedia.org/wiki/Bubble_sort)算法降序排序。 ## 冒泡排序程序，按升序排序 ```java import java.util.Scanner; class BubbleSortExample { public static void main(String []args) { int num, i, j, temp; Scanner input = new Scanner(System.in); System.out.println("Enter the number of integers to sort:"); num = input.nextInt(); int array[] = new int[num]; System.out.println("Enter " + num + " integers: "); for (i = 0; i < num; i++) array[i] = input.nextInt(); for (i = 0; i < ( num - 1 ); i++) { for (j = 0; j < num - i - 1; j++) { if (array[j] > array[j+1]) { temp = array[j]; array[j] = array[j+1]; array[j+1] = temp; } } } System.out.println("Sorted list of integers:"); for (i = 0; i < num; i++) System.out.println(array[i]); } } ``` **輸出：** ```java Enter the number of integers to sort: 6 Enter 6 integers: 12 6 78 9 45 08 Sorted list of integers: 6 8 9 12 45 78 ``` ## 冒泡排序程序，按降序排序 為了按降序排序，我們只需要將上面程序中的數組`array`的邏輯從`array[j] > array[j+1]`更改為`array[j] < array[j+1]`。完整代碼如下： ```java import java.util.Scanner; class BubbleSortExample { public static void main(String []args) { int num, i, j, temp; Scanner input = new Scanner(System.in); System.out.println("Enter the number of integers to sort:"); num = input.nextInt(); int array[] = new int[num]; System.out.println("Enter " + num + " integers: "); for (i = 0; i < num; i++) array[i] = input.nextInt(); for (i = 0; i < ( num - 1 ); i++) { for (j = 0; j < num - i - 1; j++) { if (array[j] < array[j+1]) { temp = array[j]; array[j] = array[j+1]; array[j+1] = temp; } } } System.out.println("Sorted list of integers:"); for (i = 0; i < num; i++) System.out.println(array[i]); } } ``` **輸出：** ```java Enter the number of integers to sort: 6 Enter 6 integers: 89 12 45 9 56 102 Sorted list of integers: 102 89 56 45 12 9 ```