问题解答

public class Demo
{
public static void main(String args[]){
for (int i = 1;i<=4 ;i++ )//换行程序
{
for (int b = 1;b <= i ;b++ )//输出前面的空格
{
System.out.print(" ");
}
for (int j = 1;j <= 7-2*(i-1) ;j++ )//输出号
{
System.out.print(" ");
}
System.out.println();//每写完一行进行换行
}
}
}