Java9 Series (1) Installation and jshell Use

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This article introduces the installation and use of java9 version 9 under mac.

download

Official website addresshttp://www.oracle.com/technet …

Installation path

Download hit is a pkg file, double-click the installation, the default installed to /Library/Java here, java9 Home address is

/Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home

Look at the next version

bin ./java -version
java version "9"
Java(TM) SE Runtime Environment (build 9+181)
Java HotSpot(TM) 64-Bit Server VM (build 9+181, mixed mode)

jshell

  bin ./jshell
|  欢迎使用 JShell -- 版本 9
|  要大致了解该版本, 请键入: /help intro

jshell>

With jshell, you can quickly do some verification, such as

jshell> "1,2,3,,4".split(",")
$2 ==> String[5] { "1", "2", "3", "", "4" }

jshell> "  a   b  ".trim()
$3 ==> "a   b"

imports

View imported class libraries

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.*

Method Definition and Call

jshell> String hello(){return "htllo";}
|  已创建 方法 hello()

jshell> String hello(){return "hello";}
|  已修改 方法 hello()

jshell>

jshell>

jshell> /methods
|    String hello()

jshell> hello()
$7 ==> "hello"

View history

jshell> /list

   1 : int a = 1;
   2 : "1,2,3,,4".split(",")
   3 : "  a   b  ".trim()
   4 : new Date()
   6 : String hello(){return "hello";}
   7 : hello()
   8 : 1/0

doc

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