79d9012432
* fix(curriculum): tests quotes * fix(curriculum): fill seed-teardown * fix(curriculum): fix tests and remove unneeded seed-teardown
83 lines
2.1 KiB
Markdown
83 lines
2.1 KiB
Markdown
---
|
|
id: bd7123c9c549eddfaeb5bdef
|
|
title: Use Bracket Notation to Find the First Character in a String
|
|
challengeType: 1
|
|
---
|
|
|
|
## Description
|
|
<section id='description'>
|
|
<code>Bracket notation</code> is a way to get a character at a specific <code>index</code> within a string.
|
|
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.
|
|
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>.
|
|
</section>
|
|
|
|
## Instructions
|
|
<section id='instructions'>
|
|
Use <dfn>bracket notation</dfn> to find the first character in the <code>lastName</code> variable and assign it to <code>firstLetterOfLastName</code>.
|
|
<strong>Hint</strong><br>Try looking at the <code>firstLetterOfFirstName</code> variable declaration if you get stuck.
|
|
</section>
|
|
|
|
## Tests
|
|
<section id='tests'>
|
|
|
|
```yml
|
|
tests:
|
|
- text: The <code>firstLetterOfLastName</code> variable should have the value of <code>L</code>.
|
|
testString: assert(firstLetterOfLastName === 'L', 'The <code>firstLetterOfLastName</code> variable should have the value of <code>L</code>.');
|
|
- text: You should use bracket notation.
|
|
testString: assert(code.match(/firstLetterOfLastName\s*?=\s*?lastName\[.*?\]/), 'You should use bracket notation.');
|
|
|
|
```
|
|
|
|
</section>
|
|
|
|
## Challenge Seed
|
|
<section id='challengeSeed'>
|
|
|
|
<div id='js-seed'>
|
|
|
|
```js
|
|
// Example
|
|
var firstLetterOfFirstName = "";
|
|
var firstName = "Ada";
|
|
|
|
firstLetterOfFirstName = firstName[0];
|
|
|
|
// Setup
|
|
var firstLetterOfLastName = "";
|
|
var lastName = "Lovelace";
|
|
|
|
// Only change code below this line
|
|
firstLetterOfLastName = lastName;
|
|
|
|
|
|
```
|
|
|
|
</div>
|
|
|
|
|
|
### After Test
|
|
<div id='js-teardown'>
|
|
|
|
```js
|
|
(function(v){return v;})(firstLetterOfLastName);
|
|
```
|
|
|
|
</div>
|
|
|
|
</section>
|
|
|
|
## Solution
|
|
<section id='solution'>
|
|
|
|
|
|
```js
|
|
var firstLetterOfLastName = "";
|
|
var lastName = "Lovelace";
|
|
|
|
// Only change code below this line
|
|
firstLetterOfLastName = lastName[0];
|
|
```
|
|
|
|
</section>
|