Zig Academy · 课时

错误集合与 !T 联合类型

将错误作为一等值处理。

错误集合与 !T 联合类型 是 CoddyKit 上的免费 Zig Academy 课时。这是第 1 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 Zig Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Zig 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。

Errors Are Values

In Zig there are no exceptions. An error is just an ordinary value your function can return, so failure is visible in the code.

Declare an Error Set

An error set is a named group of possible errors. You list the variants much like an enum of things that can go wrong.

const FileError = error{
    NotFound,
    PermissionDenied,
};

Refer to One Error

Each member of an error set is reached with a dot. The value FileError.NotFound is a single concrete error you can return.

return FileError.NotFound;

Anonymous Error Sets

You do not always need a name. Writing error{Empty} inline creates a tiny one-off error set right where it is used.

return error.Empty;

The Bang Means Maybe-Error

The ! in a type builds an error union. The type before it is the success value; an error may appear in its place instead.

FileError!u32

Read !T Out Loud

You can read !u32 as either a u32 or an error. The single value carries both outcomes, so callers must pick one.

Two Sides of the Union

An error union has exactly two shapes at runtime: a valid payload of type T, or one of the errors from the set. Never both.

Set Before the Bang

Put the error set on the left of ! to say exactly which errors are allowed. This documents failure right in the type.

fn parse(s: []const u8) FileError!u32 {
    // ...
}

Merge Error Sets

The || operator on two error sets combines them into one. This lets a function admit errors from several sources at once.

const AllError = FileError || NetError;

anyerror Is the Superset

The built-in anyerror contains every possible error. It is convenient but loses the precision of a named set, so use it sparingly.

fn risky() anyerror!void {}

Why Sets Help

Because errors live in the type, the compiler knows every failure a function can produce. Nothing slips past you unhandled.

Quick Check

You see the type FileError!u32 on a function. What does it describe?

Recap

You met error sets, the !T union, set merging with ||, and anyerror. Errors are plain values the type system tracks for you. ✅

常见问题解答

「错误集合与 !T 联合类型」课时是免费的吗？

是的 — 「错误集合与 !T 联合类型」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 Zig Academy 课程的其余内容，请升级到 CoddyKit PRO。 Zig Academy 课程共包含 4 节课。

「错误集合与 !T 联合类型」这节课中我会学到什么？

将错误作为一等值处理。你通过在浏览器中直接运行的动手代码来练习 Zig 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 Zig Academy 需要有经验吗？

无需任何先前经验。CoddyKit 上的 Zig 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 1 节课，共 4 节。

「错误集合与 !T 联合类型」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 Zig Academy 课中编写并运行代码吗？

能。每节 Zig 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 Zig Academy