jshell

Question: How to take user input in jshell script ? or what I'm doing wrong? Note: I'm NOT looking how to pass arguments to jshell script . Example: For example script hello.java : Scanner in = new Scanner(System.in); System.out.print("Enter number n1: "); int n1 = in.nextInt(); System.out.print("Enter number n2: "); int n2 = in.nextInt(); System.out.println("n1 + n2 = "+ (n1 +n2)); /exit It works if I type line by line in jshell, but then I run jshell hello.java it doesn't. Throws java.util.NoSuchElementException . Output I getting: @myMint ~/Java $ jshell hello.java Enter number n1: | java

As from the documentation of /set feedback in jshell, there are following built-in modes: verbose, normal, concise, and silent Is it possible to create a feedback mode with the functionality of both concise and silent? Or we can change any one of the above mode? Or can we create our own custom feedback mode? You can create your own custom feedback mode using the command: /set mode <your-mode-name> -command|-quiet where the -command option indicates that you want command feedback. If you don't want commands to describe the action that occurred, then use -quiet instead of -command . If you want

Why does my jshell instance (JDK Version 9-ea) unable to identify printf() statement ? Below is the error I observe, jshell> printf("Print number one - %d",1) | Error: | cannot find symbol | symbol: method printf(java.lang.String,int) | printf("Print number one - %d",1) | ^----^ I am able to access printf, provided I specify it in a regular way. jshell> System.out.printf("Print number one - %d",1) Print number one - 1$1 ==> java.io.PrintStream@1efbd816 Any pointers? An earlier version of JShell had a printf method pre-defined but it was removed from early access builds. You can of course

It seems, that JShell object created inside another JShell does not have access to parent's JShell scope. For instance: jshell> int x = 1; x ==> 1 jshell> x x ==> 1 jshell> jdk.jshell.JShell js = jdk.jshell.JShell.create(); js ==> jdk.jshell.JShell@1a052a00 jshell> js.eval("x"); $4 ==> [SnippetEvent(snippet=Snippet:ErroneousKey#1-x,previousStatus=NONEXISTENT,status=REJECTED,isSignatureChange=false,causeSnippetnull)] jshell> js.eval("int x = 2;"); $5 ==> [SnippetEvent(snippet=Snippet:VariableKey(x)#2-int x = 2;,previousStatus=NONEXISTENT,status=VALID,isSignatureChange=true,causeSnippetnullvalue

I went through a couple of tutorials for JShell and I still do not understand the most important part: why would I even use JShell? Here what Oracle says: "You can test individual statements, try out different variations of a method, and experiment with unfamiliar APIs within the JShell session". Yes, great, but for all those things I can just use an IDE. I do understand, that REPL should make code evaluation faster. However, testing a snippet of code in IDE in a dummy Hello World project with Sysout is for sure not slower? In fact, IDEs provide autocomplete, detect errors early and I can

I write a Java method in JShell and now I want to debug it. I would like to set breakpoints or at least step through an execution line-by-line. Does JShell have these debugging abilities? Just to clarify further, from the JEP: The Java Shell (Read-Eval-Print Loop) itself, the Non-Goals states : Out of scope are graphical interfaces and debugger support . The JShell API is intended to allow JShell functionality in IDEs and other tools, but the jshell tool is not intended to be an IDE . There is some undocumented /debug command (Jshell in Java 11). After /help /debug command you can see: jshell>