bd68b70f3d
* fix: remove isHidden flag from frontmatter * fix: add isUpcomingChange Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com> * feat: hide blocks not challenges Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com> Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com>
86 lines
1.9 KiB
Markdown
86 lines
1.9 KiB
Markdown
---
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id: bd7123c9c549eddfaeb5bdef
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title: Use Bracket Notation to Find the First Character in a String
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/ca8JwhW'
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forumTopicId: 18341
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---
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## Description
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<section id='description'>
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<dfn>Bracket notation</dfn> is a way to get a character at a specific <code>index</code> within a string.
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Most modern programming languages, like JavaScript, don't start counting at 1 like humans do. They start at 0. This is referred to as <dfn>Zero-based</dfn> indexing.
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For example, the character at index 0 in the word "Charles" is "C". So if <code>var firstName = "Charles"</code>, you can get the value of the first letter of the string by using <code>firstName[0]</code>.
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Example:
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```js
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var firstName = "Charles";
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var firstLetter = firstName[0]; // firstLetter is "C"
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```
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</section>
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## Instructions
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<section id='instructions'>
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Use bracket notation to find the first character in the <code>lastName</code> variable and assign it to <code>firstLetterOfLastName</code>.
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<strong>Hint: </strong> Try looking at the example above if you get stuck.
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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>firstLetterOfLastName</code> variable should have the value of <code>L</code>.
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testString: assert(firstLetterOfLastName === 'L');
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- text: You should use bracket notation.
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testString: assert(code.match(/firstLetterOfLastName\s*?=\s*?lastName\[.*?\]/));
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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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// Setup
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var firstLetterOfLastName = "";
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var lastName = "Lovelace";
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// Only change code below this line
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firstLetterOfLastName = lastName; // Change this line
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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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(function(v){return v;})(firstLetterOfLastName);
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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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var firstLetterOfLastName = "";
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var lastName = "Lovelace";
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// Only change code below this line
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firstLetterOfLastName = lastName[0];
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```
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</section>
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