Kotlin Multiplatform Academy · 课时

internal 与 public 可见性

有意识地控制模块的公开范围

第 2 / 4 课13 个步骤

internal 与 public 可见性 是 CoddyKit 上的免费 Kotlin Multiplatform Academy 课时。这是第 2 节课，共 4 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 Kotlin Multiplatform Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Kotlin Multiplatform Academy 课程共包含 4 节课。

本课时的部分内容尚未翻译，以英文显示。

Visibility Controls Access

Kotlin visibility modifiers decide who can call your code. They are how you separate the module's front door from its private rooms.

public Is the Default

If you write nothing, a declaration is public. That means everyone, including both apps, can see and call it from outside the module.

fun greet(name: String) = "Hi, " + name

internal Means Module-Only

The internal modifier limits a declaration to its own module. Outside code, like the Android or iOS app, simply cannot see it.

internal fun buildHeader(): String = "X-App: 1"

private Is Tightest

A private member is visible only inside its file or class. Use it for tiny helpers that nobody else should ever touch.

private fun clamp(x: Int) = x.coerceIn(0, 100)

Public Is Your Contract

Treat every public declaration as a promise to callers. Once apps depend on it, changing it can break their builds.

internal for Plumbing

Networking glue, mappers, and helpers are plumbing. Mark them internal so they support your API without becoming part of it.

Default to Closed

Start everything as internal or private, then open only what callers truly need. It is far safer than opening everything by habit.

What Module Means Here

For internal, a module is a set of files compiled together, like your shared Gradle module. The apps are separate modules.

Smaller Surface, Safer Changes

Hiding plumbing shrinks your public surface. With less exposed, you can refactor internals freely without scaring any callers. 🔒

Visibility on Properties Too

Modifiers apply to properties and classes, not just functions. A class can be public while its fields stay private inside.

class Cart {
    private var items = 0
    val count: Int get() = items
}

Internal in Both Apps

Because internal hides things across the module boundary, neither the Android app nor the iOS app sees them, keeping the API tidy.

Quick Check

Let's check how internal behaves.

在交互式课程中回答

Recap

public is your contract, internal hides plumbing in the module, and private locks down helpers. Default to closed for a clean API. 🎉

免费开始

用 AI 导师学习 Kotlin — 免费

在浏览器中编写并运行真实代码，获得全天候 AI 导师的即时帮助，并在网页或应用中继续学习。

课程: 30
课程: 120

免费开始学习查看完整课程

常见问题解答

「internal 与 public 可见性」课时是免费的吗？

是的 — 「internal 与 public 可见性」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Kotlin Multiplatform Academy 课程的其余内容，请升级到 CoddyKit PRO。 Kotlin Multiplatform Academy 课程共包含 4 节课。

「internal 与 public 可见性」这节课中我会学到什么？

有意识地控制模块的公开范围你通过在浏览器中直接运行的动手代码来练习 Kotlin Multiplatform Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 Kotlin Multiplatform Academy 需要有经验吗？

无需任何先前经验。CoddyKit 上的 Kotlin Multiplatform Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。这是第 2 节课，共 4 节。

「internal 与 public 可见性」课时需要多长时间？

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。

我能在这节 Kotlin Multiplatform Academy 课中编写并运行代码吗？

能。每节 Kotlin Multiplatform Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。

此课程中的所有课时

← 返回 Kotlin Multiplatform Academy