Clojure 与 JVM 入门

Clojure is a modern, dynamic, functional Lisp built for concurrency. It runs on the JVM, so you inherit a huge ecosystem.

Clojure stands on four ideas: functional style, immutable data, built-in concurrency, and a consistent Lisp syntax of parentheses.

Clojure compiles to JVM bytecode, which hands you the Java ecosystem, mature runtime performance, and write-once cross-platform reach.

The JVM executes Java bytecode and handles memory and garbage collection, running your code consistently across operating systems.

You work with Clojure through the official CLI tools, which run programs, manage dependencies, and launch the REPL.

Here is Hello World. Note the parentheses — that is Lisp. You define a -main function and call println.

Decoding it: ns sets a namespace, defn defines a function, and a call is just (function args) wrapped in parens.

Save the file and run it with clj -M hello.clj; the Clojure runtime executes your main and prints the result.

The REPL (Read-Eval-Print Loop) is an interactive console — type code, see results instantly. It is the heart of Clojure development.

Based on what we've learned, choose the best description of Clojure's relationship with the JVM.

Recap: Clojure is a functional Lisp on the JVM built on immutability and concurrency, and you ran Hello World and met the REPL.