99 lines
2.1 KiB
Markdown
99 lines
2.1 KiB
Markdown
---
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id: 56533eb9ac21ba0edf2244bf
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title: Local Scope and Functions
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cd62NhM'
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forumTopicId: 18227
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---
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## Description
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<section id='description'>
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Variables which are declared within a function, as well as the function parameters have <dfn>local</dfn> scope. That means, they are only visible within that function.
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Here is a function <code>myTest</code> with a local variable called <code>loc</code>.
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```js
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function myTest() {
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var loc = "foo";
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console.log(loc);
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}
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myTest(); // logs "foo"
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console.log(loc); // loc is not defined
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```
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<code>loc</code> is not defined outside of the function.
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</section>
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## Instructions
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<section id='instructions'>
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The editor has two `console.log`s to help you see what is happening. Check the console as you code to see how it changes. Declare a local variable `myVar` inside `myLocalScope` and run the tests.
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**Note:** The console will still have 'ReferenceError: myVar is not defined', but this will not cause the tests to fail.
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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: The code should not contain a global <code>myVar</code> variable.
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testString: |
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function declared(){
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myVar;
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}
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assert.throws(declared, ReferenceError);
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- text: You should add a local <code>myVar</code> variable.
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testString: assert(/functionmyLocalScope\(\)\{.+(var|let|const)myVar[\s\S]*}/.test(code.replace(/\s/g, '')));
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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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function myLocalScope() {
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'use strict';
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// Only change code below this line
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console.log('inside myLocalScope', myVar);
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}
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myLocalScope();
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// Run and check the console
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// myVar is not defined outside of myLocalScope
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console.log('outside myLocalScope', myVar);
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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 myLocalScope() {
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'use strict';
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// Only change code below this line
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var myVar;
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console.log('inside myLocalScope', myVar);
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}
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myLocalScope();
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// Run and check the console
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// myVar is not defined outside of myLocalScope
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console.log('outside myLocalScope', myVar);
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```
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</section>
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