Java利用for循环打印菱形的实例教程

Java for循环打印菱形

Java代码输出菱形的方法和思路有很多，在此分享一个稍带模块化拆分思想的解决方案，将需要输出的菱形拆分成8个模块（如下图），每个模块独立实现输出。

优点：8个模块之间耦合性降低，灵活性增强。也就是说我们可以独立的控制这8个模块中任意一个模块的输出内容来灵活应对业务逻辑的变更。

按照上图标好的顺序依次实现这8个模块的代码，当1458模块输出为空格时，其中2367模块的组合，就是一个菱形。

思路分析：

1      ######*######  第一排 模块1[6个"#"]+模块2[1个"*"]+模块3[0个"*"]+模块4[6个"#"]
        2      #####***#####
        3      ####*****####
        4      ###*******###
        5      ##*********##
        6      #***********#
    --------------------------------------------------------
        7      ##*********##  第七排 模块5[2个"#"]+模块6[5个"*"]+模块7[4个"*"]+模块8[2个"#"]
        8      ###*******###
        9      ####*****####
       10      #####***#####
       11      ######*######

代码示例：

1. public class Demo {
2.  
3. public static void main(String[] args) {
4.  
5. //为了输出效果在输出时将思路分析中的"#"替换为" "空格输出
6.  
7. for (int i = 1; i <= 11; i++) {
8.  
9. if (i <= 6) {
10. //当i <=6时打印上三角形
11. //模块 1
12. for (int j = 6; j >= i; j--) {
13. System.out.print(" ");
14. }
15. //模块 2
16. for (int j = 0; j < i; j++) {
17. System.out.print("*");
18. }
19. //模块 3[同一排中模块3的"*"个数总比模块2少1个，所以这里j <i-1作为循环条件即可]
20. for (int j = 0; j < i - 1; j++) {
21. System.out.print("*");
22. }
23. //模块 4
24. for (int j = 6; j >= i; j--) {
25. System.out.print(" ");
26. }
27. //换行
28. System.out.println();
29. } else {
30. //当i >6时打印下三角形
31. //模块 5
32. for (int j = 7; j <= i + 1; j++) {
33. System.out.print(" ");
34. }
35. //模块 6
36. for (int j = 11; j >= i; j--) {
37. System.out.print("*");
38. }
39. //模块 7
40. for (int j = 11; j >= i + 1; j--) {
41. System.out.print("*");
42. }
43. //模块 8
44. for (int j = 7; j <= i + 1; j++) {
45. System.out.print(" ");
46. }
47.  
48. //换行
49. System.out.println();
50. }
51. }
52. }
53. }

运行结果：

F:\software\Java\jdk1.8.0_121\bin\java.exe "-javaagent:D:\IntelliJ IDEA 2019.1.4\lib\idea_rt.jar=50753:D:\IntelliJ IDEA 2019.1.4\bin" -Dfile.encoding=UTF-8 -classpath F:\software\Java\jdk1.8.0_121\jre\lib\charsets.jar;F:\software\Java\jdk1.8.0_121\jre\lib\deploy.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\access-bridge-64.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\cldrdata.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\dnsns.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\jaccess.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\jfxrt.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\localedata.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\nashorn.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\sunec.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\sunjce_provider.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\sunmscapi.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\sunpkcs11.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\zipfs.jar;F:\software\Java\jdk1.8.0_121\jre\lib\javaws.jar;F:\software\Java\jdk1.8.0_121\jre\lib\jce.jar;F:\software\Java\jdk1.8.0_121\jre\lib\jfr.jar;F:\software\Java\jdk1.8.0_121\jre\lib\jfxswt.jar;F:\software\Java\jdk1.8.0_121\jre\lib\jsse.jar;F:\software\Java\jdk1.8.0_121\jre\lib\management-agent.jar;F:\software\Java\jdk1.8.0_121\jre\lib\plugin.jar;F:\software\Java\jdk1.8.0_121\jre\lib\resources.jar;F:\software\Java\jdk1.8.0_121\jre\lib\rt.jar;D:\ideastudyspace\spring_study\spring-study\spring-study-aop\target\classes;E:\software\MavenRepository\org\aspectj\aspectjweaver\1.9.4\aspectjweaver-1.9.4.jar;E:\software\MavenRepository\org\springframework\spring-webmvc\5.2.0.RELEASE\spring-webmvc-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-aop\5.2.0.RELEASE\spring-aop-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-beans\5.2.0.RELEASE\spring-beans-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-context\5.2.0.RELEASE\spring-context-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-core\5.2.0.RELEASE\spring-core-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-jcl\5.2.0.RELEASE\spring-jcl-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-expression\5.2.0.RELEASE\spring-expression-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-web\5.2.0.RELEASE\spring-web-5.2.0.RELEASE.jar;E:\software\MavenRepository\com\alibaba\fastjson\1.2.47\fastjson-1.2.47.jar com.shiguang.test.Demo
      *     
     ***    
    *****   
   *******  
  ********* 
 ***********
  ********* 
   *******  
    *****   
     ***    
      *

Process finished with exit code 0

业务变更： 打印一个空心菱形

此时只需要将1458模块输出为"*"，2367模块输出为空格即可得到一个空心菱形。

代码示例：

1. public class Demo2 {
2.  
3. public static void main(String[] args) {
4.  
5. for (int i = 1; i <= 11; i++) {
6.  
7. if (i <= 6) {
8. //当i <=6时打印上三角形
9. //模块 1
10. for (int j = 6; j >= i; j--) {
11. System.out.print("*");
12. }
13. //模块 2
14. for (int j = 0; j < i; j++) {
15. System.out.print(" ");
16. }
17. //模块 3[同一排中模块3的"*"个数总比模块2少1个，所以这里j <i-1作为循环条件即可]
18. for (int j = 0; j < i - 1; j++) {
19. System.out.print(" ");
20. }
21. //模块 4
22. for (int j = 6; j >= i; j--) {
23. System.out.print("*");
24. }
25. //换行
26. System.out.println();
27. } else {
28. //当i >6时打印下三角形
29. //模块 5
30. for (int j = 7; j <= i + 1; j++) {
31. System.out.print("*");
32. }
33. //模块 6
34. for (int j = 11; j >= i; j--) {
35. System.out.print(" ");
36. }
37. //模块 7
38. for (int j = 11; j >= i + 1; j--) {
39. System.out.print(" ");
40. }
41. //模块 8
42. for (int j = 7; j <= i + 1; j++) {
43. System.out.print("*");
44. }
45.  
46. //换行
47. System.out.println();
48. }
49. }
50. }
51. }

运行结果：

F:\software\Java\jdk1.8.0_121\bin\java.exe "-javaagent:D:\IntelliJ IDEA 2019.1.4\lib\idea_rt.jar=50681:D:\IntelliJ IDEA 2019.1.4\bin" -Dfile.encoding=UTF-8 -classpath F:\software\Java\jdk1.8.0_121\jre\lib\charsets.jar;F:\software\Java\jdk1.8.0_121\jre\lib\deploy.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\access-bridge-64.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\cldrdata.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\dnsns.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\jaccess.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\jfxrt.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\localedata.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\nashorn.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\sunec.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\sunjce_provider.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\sunmscapi.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\sunpkcs11.jar;F:\software\Java\jdk1.8.0_121\jre\lib\ext\zipfs.jar;F:\software\Java\jdk1.8.0_121\jre\lib\javaws.jar;F:\software\Java\jdk1.8.0_121\jre\lib\jce.jar;F:\software\Java\jdk1.8.0_121\jre\lib\jfr.jar;F:\software\Java\jdk1.8.0_121\jre\lib\jfxswt.jar;F:\software\Java\jdk1.8.0_121\jre\lib\jsse.jar;F:\software\Java\jdk1.8.0_121\jre\lib\management-agent.jar;F:\software\Java\jdk1.8.0_121\jre\lib\plugin.jar;F:\software\Java\jdk1.8.0_121\jre\lib\resources.jar;F:\software\Java\jdk1.8.0_121\jre\lib\rt.jar;D:\ideastudyspace\spring_study\spring-study\spring-study-aop\target\classes;E:\software\MavenRepository\org\aspectj\aspectjweaver\1.9.4\aspectjweaver-1.9.4.jar;E:\software\MavenRepository\org\springframework\spring-webmvc\5.2.0.RELEASE\spring-webmvc-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-aop\5.2.0.RELEASE\spring-aop-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-beans\5.2.0.RELEASE\spring-beans-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-context\5.2.0.RELEASE\spring-context-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-core\5.2.0.RELEASE\spring-core-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-jcl\5.2.0.RELEASE\spring-jcl-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-expression\5.2.0.RELEASE\spring-expression-5.2.0.RELEASE.jar;E:\software\MavenRepository\org\springframework\spring-web\5.2.0.RELEASE\spring-web-5.2.0.RELEASE.jar;E:\software\MavenRepository\com\alibaba\fastjson\1.2.47\fastjson-1.2.47.jar com.shiguang.test.Demo
****** ******
*****   *****
****     ****
***       ***
**         **
*           *
**         **
***       ***
****     ****
*****   *****
****** ******

Process finished with exit code 0

总结

到此这篇关于Java利用for循环打印菱形的文章就介绍到这了,更多相关Java for循环打印菱形内容请搜索服务器之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持服务器之家！

原文链接：https://blog.csdn.net/weixin_45333509/article/details/115253945