【编程小技巧】

输出内容覆盖原有的内容

\r表示回车符，会将光标移至开始位置，同时使用非换行形式的print

public class Main {
    public static void main(String[] args) {
        Random r = new Random();
        String[] all = new String[10];
        for (int i = 0; i <= 100; i++) {
            try {
                Thread.sleep(r.nextInt(100));
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            all[0] = i + "%";
            System.out.print("\r" +Arrays.toString(all));
        }
    }
}