数据结构
网络
RDBMS
操作系统
Java
MS Excel
iOS
HTML
CSS
Android
Python
C 编程
C++
C#
MongoDB
MySQL
Javascript
PHP
物理学
化学
生物
数学
英语
经济学
心理学
社会科学
时尚研究
法律研究Java 9 中的 JShell？
JShell 是 Java 9 版本中引入的一个新概念。它提供了 Java 的REPL （Read-Eval-Print-Loop，读取-求值-打印-循环）功能。使用 JShell，我们可以在不进行编译的情况下测试基于 Java 的逻辑和表达式 。REPL 充当了一个即时反馈循环，并对此特定语言中的生产力产生了巨大影响。
步骤 1：打开命令提示符并键入JShell。
Microsoft Windows [Version 6.3.9600] (c) 2013 Microsoft Corporation. All rights reserved. C:\Users\User>JShell | Welcome to JShell -- Version 9.0.4 | For an introduction type: /help intro jshell>
步骤 2：在 JShell 命令窗口中键入/help（查看 JShell 命令），并在它开始运行后。使用此命令。
jshell> /help | Type a Java language expression, statement, or declaration. | Or type one of the following commands: | /list [|-all|-start] | list the source you have typed | /edit | edit a source entry referenced by name or id | /drop | delete a source entry referenced by name or id | /save [-all|-history|-start] | Save snippet source to a file. | /open | open a file as source input | /vars [|-all|-start] | list the declared variables and their values | /methods [|-all|-start] | list the declared methods and their signatures | /types [|-all|-start] | list the declared types | /imports | list the imported items | /exit | exit jshell | /env [-class-path ] [-module-path ] [-add-modules < | view or change the evaluation context | /reset [-class-path ] [-module-path ] [-add-modules | reset jshell | /reload [-restore] [-quiet] [-class-path ] [-module-path | reset and replay relevant history -- current or previous ( | /history | history of what you have typed | /help [|] | get information about jshell | /set editor|start|feedback|mode|prompt|truncation|format ... | set jshell configuration information | /? [|] | get information about jshell | /! | re-run last snippet | / | re-run snippet by id | /- | re-run n-th previous snippet | | For more information type '/help' followed by the name of a | command or a subject. | For example '/help /list' or '/help intro'. | | Subjects: | | intro | an introduction to the jshell tool | shortcuts | a description of keystrokes for snippet and command comple | information access, and automatic code generation | context | the evaluation context options for /env /reload and /reset
步骤 3：在 JShell 命令窗口中键入/imports来获取 JShell 导入的软件包。
jshell> /imports | import java.io.* | import java.math.* | import java.net.* | import java.nio.file.* | import java.util.* | import java.util.concurrent.* | import java.util.function.* | import java.util.prefs.* | import java.util.regex.* | import java.util.stream.*
步骤 4：在 JShell 中执行计算（使用 JShell 尝试算术计算）
jshell> 3+5 $1 ==> 8 jshell> 8-4 $2 ==> 4 jshell> 2*6 $3 ==> 12 jshell> 9%3 $4 ==> 0 jshell> 8/2 $5 ==> 4
步骤 5：要退出 JShell，请键入/exit。
jshell> /exit | Goodbye
更新于： 17-2-2020
157 次浏览
广告