Zig Academy · 课时

多项指针 [*]T

指向一段连续的元素。

多项指针 [*]T 是 CoddyKit 上的免费 Zig Academy 课时。这是第 3 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。

Pointing at a Run

Sometimes a pointer addresses not one value but the start of a sequence of values laid out in memory. 🧱

The [*]T Type

A many-item pointer is written [*]T. The star inside the brackets means it points at an unknown number of T values in a row.

var run: [*]u8 = undefined;

No Length Attached

Unlike a slice, a many-item pointer carries no length. You alone must know how many elements are safe to touch.

Index Like an Array

You can index a many-item pointer with brackets, so run[2] reaches the third element by stepping forward in memory.

const third = run[2];

Pointer Arithmetic

Adding to a many-item pointer moves it by whole elements, so run + 1 points one T further along, not one byte.

const next = run + 1;

Single vs Many

A *T points at exactly one value and cannot be indexed; a [*]T points at many and supports indexing and arithmetic.

Where They Come From

Many-item pointers often appear when talking to C, which passes a bare pointer to a buffer with the length tracked separately.

No Bounds Checks

Because the length is unknown, indexing a many-item pointer is not bounds-checked. Reading too far is undefined behavior.

Prefer Slices

When you control the code, a slice []T is safer because it bundles the length. Reach for [*]T mainly at C boundaries.

From Pointer to Slice

Once you know the count, attach a length with ptr[0..n] to turn a many-item pointer into a safe, bounds-checked slice.

const view = run[0..n];

Sentinel Variants Exist

Zig also has sentinel-terminated forms like [*:0]u8, a pointer whose run ends at a known value such as a zero byte.

var cstr: [*:0]const u8 = "hi";

Quick Check

Compare a slice []T with a many-item pointer [*]T. What does the many-item pointer lack?

Recap

A many-item pointer [*]T addresses a run of values, supports indexing and arithmetic, has no length, and is best converted to a slice when possible. 🎯

常见问题解答

「多项指针 [*]T」课时是免费的吗？

是的 — 「多项指针 [*]T」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。

「多项指针 [*]T」这节课中我会学到什么？

指向一段连续的元素。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 3 节课，共 4 节。

「多项指针 [*]T」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