代码如下：

public class MyWork {
    public static void main(String[] args) {
        int num = 5;
        for (int i = 0; i < num; i++) {
            for (int j = 0; j <= i; j++) {
                System.out.print("-");
            }
            for (int j = 0; j < num - i; j++) {
                System.out.print("*");
            }
            System.out.println();
        }
    }
}