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Java Java Objects Meet Objects Welcome Back

Diego Silva
Diego Silva
313 Points
Posted by Diego Silva
Diego Silva
313 Points

Jshell- REPLL

Hi guys

I didn't get the idea of the Jshell. Why do we need to use that? In some of his examples, I got confused, like those where we had $7==> Where this number came from?

2 Answers

Deneen Edwards
Deneen Edwards
5,626 Points
Deneen Edwards
Deneen Edwards
5,626 Points

The Java Shell tool (JShell) is an interactive tool for learning the Java programming language and prototyping Java code. JShell is a Read-Evaluate-Print Loop (REPL), which evaluates declarations, statements, and expressions as they are entered and immediately shows the results. JShell helps you try out code and easily explore options as you develop your program. You can test individual statements, try out different variations of a method, and experiment with unfamiliar APIs within the JShell session. .... When an expression is entered that doesn't have a named variable (such as you enter jshell> 5 + 5), a scratch variable (such as $7) is created so that the value can be referenced later.
(jshell will return something like: $7 ==> 10) In other words, it's just an auto-generated variable name. But if you entered jshell> int myNum = 5 + 5..............jshell will return: myNum ==> 10

Darth R3id4k
PLUS
Darth R3id4k
Courses Plus Student 10,125 Points
Darth R3id4k
Darth R3id4k
Courses Plus Student 10,125 Points

$ is nothing more than just ID (or dynamic implicitly consecutive generated variable name) of properly handled snipet. If you use command /list you will see list of all correctly executed snippets in the current JShell session. On the left side of this list there are numbers with colon - ID. You can use this number(s) in next snipet: 11 + 5 $10: 16 20 - $10 $11: 4 You can run snipet again by typing ID number ($4) /4