java，for循环嵌套，打印菱形

public class t8 {

public static void main(String[] args) {
//上半部分
for (int m = 1; m <= 10; m++)
{
//输出空格
for (int n = 9; n >= m ;n--)
{
System.out.print(" ");
}
//输出* 左上
for (int n = 1; n <= m; n++)
{
System.out.print("*");
}

//右上
for (int n = 1; n < m; n++)
{
System.out.print("*");
}

System.out.println();
}

//下半部分
for (int m = 1; m <= 9; m++)
{
//输出空格
for (int n = 1; n <= m ;n++)
{
System.out.print(" ");
}
//输出* 左下
for (int n = 9; n >= m; n--)
{
System.out.print("*");
}

//右下
for (int n = 9; n > m; n--)
{
System.out.print("*");
}

System.out.println();
}
}
}