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while 循环与 continue 表达式

使用条件和步进操作执行循环。

while 循环与 continue 表达式 是 CoddyKit 上的免费 Zig 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 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。

Repeat with while

A while loop repeats its body as long as a bool condition stays true. It checks the condition before each pass. 🔁

while (i < 5) {
    std.debug.print("{}\n", .{i});
    i += 1;
}

Checked Before Each Pass

Zig tests the condition first, so a while whose condition starts false runs zero times. The body is never guaranteed to execute.

Avoiding Infinite Loops

Each iteration should move toward making the condition false. Forget to update the variable and the loop spins forever.

The continue Expression

Zig adds a continue expression after a colon. It runs at the end of every iteration, the perfect place for your step update.

var i: usize = 0;
while (i < 5) : (i += 1) {
    work(i);
}

Why the continue Slot Helps

Putting the step in the continue slot keeps it visible at the top and guarantees it runs even after a continue statement skips ahead.

Skip with continue

The continue statement jumps to the next iteration immediately, skipping the rest of the body but still running the continue expression.

while (i < 10) : (i += 1) {
    if (i % 2 == 0) continue;
    odd_sum += i;
}

Stop Early with break

Use break to leave a while loop right away, even when the condition is still true. Control resumes after the loop.

while (true) {
    if (done()) break;
}

while as an Expression

A while can yield a value. break supplies the result on success, and an else clause provides the value when the loop finishes normally.

const found = while (i < n) : (i += 1) {
    if (match(i)) break i;
} else null;

Looping over Optionals

A while can keep unwrapping an optional, running while values are present and ending the moment it sees null.

while (it.next()) |item| {
    process(item);
}

Looping over Errors

Like if, a while can capture an error in an else branch when the unwrapped expression returns an error union instead of a value.

Infinite Loops on Purpose

Sometimes you want a deliberate forever loop. Writing while (true) with a break inside is the idiomatic event-loop pattern in Zig.

Quick Check

Where does Zig's continue expression run during a while loop?

Recap

You drove while: condition-first looping, the continue expression for clean steps, break and continue, and the value-returning expression form. 🎯

常见问题解答

「while 循环与 continue 表达式」课时是免费的吗？

是的 — 「while 循环与 continue 表达式」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。

「while 循环与 continue 表达式」这节课中我会学到什么？

使用条件和步进操作执行循环。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 2 节课，共 4 节。

「while 循环与 continue 表达式」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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