<pre class="shiki github-dark shaku"><code>/*type Callback = (error: Error, data: any) =&gt; voidtype AsyncFunc = ( callback: Callback, data: any) =&gt; void*//** * @param {AsyncFunc[]} funcs * @return {(callback: Callback) =&gt; void} */function sequence(funcs) { return function (finalCallback, initialData) { let i = 0; const nextFunc = (newData) =&gt; { if (i===funcs.length) { return finalCallback(undefined, newData); } const currentFunc = funcs[i]; i++; currentFunc((error,data) =&gt; { if (error) { return finalCallback(error); } else { nextFunc(data); } }, newData) } nextFunc(initialData); };}</code></pre>

递归解法，next函数将上一个异步操作的输出作为下一个异步操作的输入。

This problem is similar to 11. what is Composition? create a pipe(). You are asked to implement an async function helper, sequence() which chains up a…