编译时与运行时
了解 Zig 能在运行前计算什么。
编译时与运行时 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。
Two Times in One Program
Zig code lives in two worlds: things that happen while you compile, and things that happen while the program runs. Learning the split unlocks Zig's power. ⏱️
Run-Time Is the Familiar One
Run-time is everything that happens when your built binary executes: user input, file reads, and values you cannot know in advance.
Compile-Time Happens Earlier
Compile-time is work the Zig compiler does before a binary even exists. Some expressions get fully evaluated right there.
Constants Often Fold Away
A simple expression with known values can be computed during compilation. Zig folds it into a single constant in the final binary.
const minutes = 60 * 24;comptime_int Has No Fixed Width
A bare integer literal starts life as a comptime_int. It has arbitrary precision until you pin it to a sized type like i32.
const big = 1_000_000_000_000;The comptime Keyword
Put comptime in front of an expression to demand it be evaluated during compilation. If it cannot be, you get an error.
comptime {
const x = 2 + 3;
}Run-Time Values Stay at Run-Time
A value read from input is only known when the program runs. You cannot ask the compiler to evaluate it at compile-time.
comptime Can Run Real Logic
Compile-time is not just math. Zig can run loops and call functions at compile-time, as long as every input is known then.
const total = comptime sum(10);Why Move Work to Compile-Time
Computing things during compilation means zero run-time cost. The answer is baked into the binary, so the program never recomputes it.
One Language for Both
The same Zig syntax serves both phases. There is no separate macro language: compile-time code is just ordinary Zig run early.
Errors Caught Before Run-Time
Because Zig evaluates known code early, many mistakes surface as compile errors. You fix them before the program ever runs.
Quick Check
You write a constant equal to 7 times 24. When is that multiplication performed?
Recap
Zig splits work into compile-time and run-time. Known values can be computed early for free, while unknown ones wait for execution. 🎯
常见问题解答
「编译时与运行时」课时是免费的吗？
是的 — 「编译时与运行时」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。
「编译时与运行时」这节课中我会学到什么？
了解 Zig 能在运行前计算什么。 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。
「编译时与运行时」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。