JShell helps a programmer to test fragments (snippets) of code as they are written. It shortens the time for development by avoiding the build-deploy-test part of the development cycle. Programmers can easily copy an expression or even several methods into the JShell session and run-test-modify them multiple times immediately. Such a quick turnaround also helps to understand the library API better before using it and to tune the code to express exactly its purpose, thus facilitating better quality software.
How often have we guessed what the JavaDoc for a particular API meant and wasted build-deploy-test cycles for figuring it out? Or we want to recall, how exactly the string will be split by substring(3)? Sometimes, we create a small test application where we run the code we are not sure about, using again the same build-deploy-test cycle. With JShell, we can copy, paste, and run. In this section, we will describe and show how to do it.
JShell is built on the top of...