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使用 @typeInfo 反射字段

在编译时检查类型的结构

使用 @typeInfo 反射字段 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。

Look Inside Any Type

Zig lets your code examine its own types while it compiles. The built-in @typeInfo hands you the full structure of a type as data. 🔎

It Returns a Type.Info Value

@typeInfo takes a type and returns a std.builtin.Type value. That value is a tagged union describing exactly what kind of type you passed.

const info = @typeInfo(u32);

The Tag Says What Kind It Is

The union tag tells you the category: a struct, an int, a pointer, and so on. You switch on it to react to each kind of type.

switch (@typeInfo(T)) {
    .Struct => {},
    else => {},
}

Reach the Struct Payload

When the type is a struct, the .Struct variant carries a payload describing its fields, declarations, and layout.

const s = @typeInfo(Point).Struct;

Fields Live in an Array

The struct payload has a fields array. Each entry is a StructField holding one field's name, type, and other details.

const fields = @typeInfo(Point).Struct.fields;

Read a Field's Name and Type

Each StructField exposes a name string and a type. Both are compile-time values you can print or branch on.

const f = @typeInfo(Point).Struct.fields[0];
const n = f.name;

Walk Fields with inline for

Because the field list is comptime, you iterate it with inline for. The loop unrolls, giving each field its own concrete code.

inline for (@typeInfo(T).Struct.fields) |field| {
    _ = field.name;
}

Inspect Integer Types Too

For an int, the .Int variant reveals its signedness and bit width, so you can adapt logic to the exact number type.

const i = @typeInfo(i16).Int;
const bits = i.bits;

Enums Expose Their Members

The .Enum variant lists every enum field with its name and integer value, letting you generate code per option.

const e = @typeInfo(Color).Enum;
const fields = e.fields;

Pointers Reveal Their Target

For pointers the .Pointer variant tells you the child type, size kind, and whether it is const, so you can unwrap layers.

const p = @typeInfo(*u8).Pointer;
const child = p.child;

This Powers Real Libraries

Reflection drives Zig's own JSON and formatting code: they read fields with @typeInfo and handle any struct you give them. ✨

Quick Check

You want the list of a struct's fields at compile time. Which expression gives it to you?

Recap

@typeInfo turns a type into data: switch on its tag, then read fields, bits, or members and loop them with inline for. 🎯

常见问题解答

「使用 @typeInfo 反射字段」课时是免费的吗？

是的 — 「使用 @typeInfo 反射字段」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。

「使用 @typeInfo 反射字段」这节课中我会学到什么？

在编译时检查类型的结构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。

「使用 @typeInfo 反射字段」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。

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