83 lines
1.6 KiB
Markdown
83 lines
1.6 KiB
Markdown
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---
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id: 587d7db2367417b2b2512b8b
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title: Understand the Immediately Invoked Function Expression (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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A common pattern in JavaScript is to execute a function as soon as it is declared:
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```js
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(function () {
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console.log("Chirp, chirp!");
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})(); // this is an anonymous function expression that executes right away
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// Outputs "Chirp, chirp!" immediately
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```
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Note that the function has no name and is not stored in a variable. The two parentheses () at the end of the function expression cause it to be immediately executed or invoked. This pattern is known as an <dfn>immediately invoked function expression</dfn> or <dfn>IIFE</dfn>.
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# --instructions--
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Rewrite the function `makeNest` and remove its call so instead it's an anonymous immediately invoked function expression (IIFE).
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# --hints--
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The function should be anonymous.
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```js
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assert(/\((function|\(\))(=>|\(\)){?/.test(code.replace(/\s/g, '')));
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```
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Your function should have parentheses at the end of the expression to call it immediately.
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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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