文本示例

The given program code is implementing the Bubble Sort algorithm to sort an array of integers in ascending order. Here's a breakdown of what the code does:

1. The `BubbleSort` class is defined, which contains the `main` method and the `bubbleSort` method.

2. In the `main` method:
- An integer array `arr` is initialized with values {5, 2, 8, 12, 1, 6, 3, 9, 4}.
- The `bubbleSort` method is called, passing the `arr` array as an argument.
- The statement `System.out.println(\"：\");` is used to print a separator line.

3. The `bubbleSort` method takes an integer array `arr` as a parameter:
- The length of the array is stored in the variable `n`.
- Two nested loops are used to iterate over the array elements.
- The outer loop (with variable `i`) runs from 0 to `n - 1`.
- The inner loop (with variable `j`) runs from 0 to `n - i - 1`.
- Within the inner loop, adjacent elements are compared, and if the element at index `j` is greater than the element at index `j + 1`, a swap is performed.
- This process continues until the entire array is sorted in ascending order.

4. After the `bubbleSort` method completes, the sorted array is printed using a for-each loop, with each element separated by a space.

In summary, the program uses the Bubble Sort algorithm to sort the given array of integers and then prints the sorted array.