一，jshell查看帮助
[lhdop@blog ~]$ jshell --help
Usage: jshell <option>... <load-file>...
where possible options include:
--class-path <path> Specify where to find user class files
--module-path <path> Specify where to find application modules
--add-modules <module>(,<module>)*
…
二，jshell的使用
1, -v : 详细模式启动JShel
[lhdop@blog ~]$ jshell -v | Welcome to JShell -- Version 15 | For an introduction type: /help intro jshell>
2,退出:
jshell> /exit | Goodbye
3,一个整数相加的例子:
jshell> int x = 35; x ==> 35 | created variable x : int jshell> int y = 33; y ==> 33 | created variable y : int jshell> int z = x + y; z ==> 68 | created variable z : int jshell> System.out.println(z); 68
4,jshell中使用函数
jshell> Math.pow(2,3) $1 ==> 8.0 | created scratch variable $1 : double
5,jshell中使用HashMap
jshell> HashMap<Integer,String> mapOne = new HashMap<Integer,String>();
mapOne ==> {}
| created variable mapOne : HashMap<Integer, String>
jshell> mapOne.put(35,"thirty five");
$3 ==> null
| created scratch variable $3 : String
jshell> mapOne.get(35);
$4 ==> "thirty five"
| created scratch variable $4 : String
6,jshell中自定义函数
jshell> String glue(String a,String b) {
...> return a+","+b;
...> }
| created method glue(String,String)
jshell> glue("laoliu","good")
$6 ==> "laoliu,good"
| created scratch variable $6 : String
7,jshell中的内置命令:
/vars 查看变量
jshell> /vars
| double $1 = 8.0
| HashMap<Integer, String> mapOne = {35=thirty five}
| String $3 = null
| String $4 = "thirty five”
/list 列出执行过的代码片段
jshell> /list 1 : Math.pow(2,3) 2 : HashMap<Integer,String> mapOne = new HashMap<Integer,String>(); 3 : mapOne.put(35,"thirty five"); 4 : mapOne.get(35);
/methods 列出自定义的方法
jshell> /methods | String glue(String,String)
/ 列出所有命令
jshell> / | Command: '/' is ambiguous: /list, /edit, /drop, /save, /open, /vars, /methods, /types, /imports,
/exit, /env, /reset, /reload, /history, /debug, /help, /set, /?, /! | Type /help for help.
/help 详细的帮助
jshell> /help | Type a Java language expression, statement, or declaration. | Or type one of the following commands: | /list [<name or id>|-all|-start] | list the source you have typed | /edit <name or id> | edit a source entry | /drop <name or id> | delete a source entry ...
说明：刘宏缔的架构森林—专注it技术的博客，
网址：https://imgtouch.com
本文: https://blog.imgtouch.com/index.php/2023/06/01/java-15-yong-jshell-ti-yan-jiao-hu-shi-java-bian-cheng/
代码: https://github.com/liuhongdi/ 或 https://gitee.com/liuhongdi
说明：作者:刘宏缔 邮箱: 371125307@qq.com
三，查看java的版本:
[lhdop@blog tools]$ java --version java 15 2020-09-15 Java(TM) SE Runtime Environment (build 15+36-1562) Java HotSpot(TM) 64-Bit Server VM (build 15+36-1562, mixed mode, sharing)
