108 lines
2.5 KiB
Markdown
108 lines
2.5 KiB
Markdown
---
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id: 56bbb991ad1ed5201cd392cf
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title: Write Reusable JavaScript with Functions
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challengeType: 1
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---
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## Description
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<section id='description'>
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In JavaScript, we can divide up our code into reusable parts called <dfn>functions</dfn>.
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Here's an example of a function:
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<blockquote>function functionName() {<br> console.log("Hello World");<br>}</blockquote>
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You can call or <dfn>invoke</dfn> this function by using its name followed by parentheses, like this:
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<code>functionName();</code>
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Each time the function is called it will print out the message <code>"Hello World"</code> on the dev console. All of the code between the curly braces will be executed every time the function is called.
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</section>
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## Instructions
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<section id='instructions'>
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<ol><li>Create a function called <code>reusableFunction</code> which prints <code>"Hi World"</code> to the dev console.</li><li>Call the function.</li></ol>
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>reusableFunction</code> should be a function
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testString: 'assert(typeof reusableFunction === "function", "<code>reusableFunction</code> should be a function");'
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- text: <code>reusableFunction</code> should output "Hi World" to the dev console
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testString: 'assert("Hi World" === logOutput, "<code>reusableFunction</code> should output "Hi World" to the dev console");'
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- text: Call <code>reusableFunction</code> after you define it
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testString: 'assert(/^\s*reusableFunction\(\)\s*;/m.test(code), "Call <code>reusableFunction</code> after you define it");'
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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// Example
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function ourReusableFunction() {
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console.log("Heyya, World");
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}
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ourReusableFunction();
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// Only change code below this line
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```
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</div>
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### Before Test
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<div id='js-setup'>
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```js
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var logOutput = "";
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var originalConsole = console
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function capture() {
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var nativeLog = console.log;
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console.log = function (message) {
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if(message && message.trim) logOutput = message.trim();
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if(nativeLog.apply) {
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nativeLog.apply(originalConsole, arguments);
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} else {
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var nativeMsg = Array.prototype.slice.apply(arguments).join(' ');
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nativeLog(nativeMsg);
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}
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};
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}
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function uncapture() {
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console.log = originalConsole.log;
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}
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capture();
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```
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</div>
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### After Test
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<div id='js-teardown'>
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```js
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console.info('after the test');
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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function reusableFunction() {
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console.log("Hi World");
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}
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reusableFunction();
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```
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</section>
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