84 lines
1.5 KiB
Markdown
84 lines
1.5 KiB
Markdown
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---
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id: 587d7db2367417b2b2512b8b
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title: 瞭解立即調用函數表達（IIFE）
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challengeType: 1
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forumTopicId: 301328
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dashedName: understand-the-immediately-invoked-function-expression-iife
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---
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# --description--
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JavaScript 中的一個常見模式就是，函數在聲明後立刻執行：
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```js
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(function () {
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console.log("Chirp, chirp!");
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})();
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```
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這是一個匿名函數表達式，立即執行並輸出 `Chirp, chirp!`。
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請注意，函數沒有名稱，也不存儲在變量中。 函數表達式末尾的兩個括號（）會讓它被立即執行或調用。 這種模式被叫做立即調用函數表達式（<dfn>immediately invoked function expression</dfn>) 或者<dfn>IIFE</dfn>。
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# --instructions--
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重寫函數 `makeNest`，並刪除它的調用，取而代之是一個匿名的立即調用函數表達式（IIFE）。
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# --hints--
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該函數應該是匿名的。
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```js
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assert(/\((function|\(\))(=>|\(\)){?/.test(code.replace(/\s/g, '')));
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```
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函數應該在表達式的末尾有括號，以便立即調用它。
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```js
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assert(/\(.*(\)\(|\}\(\))\)/.test(code.replace(/[\s;]/g, '')));
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```
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# --seed--
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## --seed-contents--
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```js
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function makeNest() {
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console.log("A cozy nest is ready");
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}
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makeNest();
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```
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# --solutions--
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```js
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(function () {
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console.log("A cozy nest is ready");
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})();
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```
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---
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```js
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(function () {
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console.log("A cozy nest is ready");
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}());
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```
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---
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```js
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(() => {
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console.log("A cozy nest is ready");
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})();
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```
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---
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```js
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(() =>
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console.log("A cozy nest is ready")
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)();
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```
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