用Java程序打印空心直角三角形星形图案

编写一个Java程序，使用for循环打印空心直角三角形星形图案。这个Java空心直角三角形星形例子在嵌套的for循环中使用if条件来寻找外面的行并显示空心直角三角形。

package ShapePrograms;

import java.util.Scanner;

public class HollowRightTriangle1 { private static Scanner sc;

public static void main(String\[\] args) {
	sc = new Scanner(System.in);
	
	System.out.print("Enter Hollow Right Angled Triangle Pattern Rows = ");
	int rows = sc.nextInt();
	
	System.out.println("Hollow Right Angled Triangle Star Pattern");
	
	for (int i = 1 ; i <= rows; i++ ) 
	{
		for (int j = 1 ; j <= i; j++ ) 
		{
			if(i == 1 || i == rows || j == 1 || j == i)
			{
				System.out.print("\*");
			}
			else
			{
				System.out.print(" ");
			}
		}
		System.out.println();
	}
}

在这个Java空心直角三角形星形图案程序中，我们用while循环代替for循环。

package ShapePrograms;

import java.util.Scanner;

public class HollowRightTriangle2 { private static Scanner sc;

public static void main(String\[\] args) {
	sc = new Scanner(System.in);
	
	System.out.print("Enter Hollow Right Angled Triangle Pattern Rows = ");
	int rows = sc.nextInt();
	
	System.out.println("Hollow Right Angled Triangle Star Pattern");
	int i = 1, j ;
	
	while( i <= rows) 
	{
		j = 1 ;
		while( j <= i ) 
		{
			if(i == 1 || i == rows || j == 1 || j == i)
			{
				System.out.print("\*");
			}
			else
			{
				System.out.print(" ");
			}
			j++;
		}
		System.out.println();
		i++ ;
	}
}

Enter Hollow Right Angled Triangle Pattern Rows = 11
Hollow Right Angled Triangle Star Pattern
*
**
* *
*  *
*   *
*    *
*     *
*      *
*       *
*        *
***********

使用do while循环打印空心直角三角形星形图案的Java程序

package ShapePrograms;

import java.util.Scanner;

public class HollowRightTriangle3 { private static Scanner sc;

public static void main(String\[\] args) {
	sc = new Scanner(System.in);
	
	System.out.print("Enter Hollow Right Angled Triangle Pattern Rows = ");
	int rows = sc.nextInt();
	
	System.out.println("Hollow Right Angled Triangle Star Pattern");
	int i = 1, j ;
	
	do
	{
		j = 1 ;
		do
		{
			if(i == 1 || i == rows || j == 1 || j == i)
			{
				System.out.print("\*");
			}
			else
			{
				System.out.print(" ");
			}
		} while( ++j <= i );
		System.out.println();
	} while( ++i <= rows) ;
}

Enter Hollow Right Angled Triangle Pattern Rows = 14
Hollow Right Angled Triangle Star Pattern
*
**
* *
*  *
*   *
*    *
*     *
*      *
*       *
*        *
*         *
*          *
*           *
**************

在这个Java例子中，HollowRightTrianglePat函数打印出一个给定符号的空心直角三角形图案。

package ShapePrograms;

import java.util.Scanner;

public class HollowRightTriangle4 { private static Scanner sc;

public static void main(String\[\] args) {
	sc = new Scanner(System.in);
	
	System.out.print("Enter Hollow Right Angled Triangle Pattern Rows = ");
	int rows = sc.nextInt();
	
	System.out.print("Character for Hollow Right Angled Triangle Pattern = ");
	char ch = sc.next().charAt(0);
	
	System.out.println("Hollow Right Angled Triangle Pattern");
	HollowRightTrianglePat(rows, ch);
}

public static void HollowRightTrianglePat(int rows, char ch) {
	for (int i = 1 ; i <= rows; i++ ) 
	{
		for (int j = 1 ; j <= i; j++ ) 
		{
			if(i == 1 || i == rows || j == 1 || j == i)
			{
				System.out.print(ch);
			}
			else
			{
				System.out.print(" ");
			}
		}
		System.out.println();
	}
}

Enter Hollow Right Angled Triangle Pattern Rows = 18
Character for Hollow Right Angled Triangle Pattern = #
Hollow Right Angled Triangle Pattern
#
##
# #
#  #
#   #
#    #
#     #
#      #
#       #
#        #
#         #
#          #
#           #
#            #
#             #
#              #
#               #
##################