สคริปต์ Groovy และ GShell

A Groovy script is just a file of code that runs directly — no main method required. Perfect for automation and quick utilities.

A Groovy script needs no class or method wrapper — the file itself is the entry point. Just write your lines and run them.

Save your code with a .groovy extension, then run it from the terminal with groovy myScript.groovy. That is the whole workflow.

This script adds two numbers and branches with an if — a quick taste of how natural and readable Groovy scripting feels.

Scripts can talk to the user too. Read a line from the console with System.in.newReader().readLine(), as shown below.

The GroovyShell (groovysh) is an interactive console — run snippets instantly, test ideas, and get feedback without saving a file.

Type groovysh to launch the interactive shell, or groovyConsole for the GUI version. We will stick with the command-line one here.

Inside groovysh, type any Groovy and it runs immediately, showing the result after ===>. Type :exit when you are done.

GShell has colon commands for managing your session: :help, :history, :clear, and :reset to wipe declared variables.

GShell shines for instant experiments — call a method or transform a list and see the result right away, no file, compile, or run step.

Consider the following Groovy code snippet:

Where would you typically execute this snippet if you want to save it for later use and run it repeatedly?

You learned the two core Groovy tools: scripts for repeatable .groovy files, and the GroovyShell for instant experimentation.