---
id: 587d7db2367417b2b2512b8c
title: Use an IIFE to Create a Module
challengeType: 1
---
## Description
<section id='description'>
An <code>immediately invoked function expression</code> (<code>IIFE</code>) is often used to group related functionality into a single object or <code>module</code>. For example, an earlier challenge defined two mixins:
<blockquote>function glideMixin(obj) {<br> obj.glide = function() {<br> console.log("Gliding on the water");<br> };<br>}<br>function flyMixin(obj) {<br> obj.fly = function() {<br> console.log("Flying, wooosh!");<br> };<br>}</blockquote>
We can group these <code>mixins</code> into a module as follows:
<blockquote>let motionModule = (function () {<br> return {<br> glideMixin: function(obj) {<br> obj.glide = function() {<br> console.log("Gliding on the water");<br> };<br> },<br> flyMixin: function(obj) {<br> obj.fly = function() {<br> console.log("Flying, wooosh!");<br> };<br> }<br> }<br>})(); // The two parentheses cause the function to be immediately invoked</blockquote>
Note that you have an <code>immediately invoked function expression</code> (<code>IIFE</code>) that returns an object <code>motionModule</code>. This returned object contains all of the <code>mixin</code> behaviors as properties of the object.
The advantage of the <code>module</code> pattern is that all of the motion behaviors can be packaged into a single object that can then be used by other parts of your code. Here is an example using it:
<blockquote>motionModule.glideMixin(duck);<br>duck.glide();</blockquote>
</section>
## Instructions
<section id='instructions'>
Create a <code>module</code> named <code>funModule</code> to wrap the two <code>mixins</code> <code>isCuteMixin</code> and <code>singMixin</code>. <code>funModule</code> should return an object.
</section>
## Tests
<section id='tests'>
```yml
tests:
- text: <code>funModule</code> should be defined and return an object.
testString: assert(typeof funModule === "object", '<code>funModule</code> should be defined and return an object.');
- text: <code>funModule.isCuteMixin</code> should access a function.
testString: assert(typeof funModule.isCuteMixin === "function", '<code>funModule.isCuteMixin</code> should access a function.');
- text: <code>funModule.singMixin</code> should access a function.
testString: assert(typeof funModule.singMixin === "function", '<code>funModule.singMixin</code> should access a function.');
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='js-seed'>
```js
let isCuteMixin = function(obj) {
obj.isCute = function() {
return true;
};
};
let singMixin = function(obj) {
obj.sing = function() {
console.log("Singing to an awesome tune");
};
};
```
</div>
</section>
## Solution
<section id='solution'>
```js
const funModule = (function () {
return {
isCuteMixin: obj => {
obj.isCute = () => true;
},
singMixin: obj => {
obj.sing = () => console.log("Singing to an awesome tune");
}
};
})();
```
</section>