77 lines
2.3 KiB
Markdown
77 lines
2.3 KiB
Markdown
---
|
|
id: 587d7dbb367417b2b2512bab
|
|
title: Use Capture Groups to Search and Replace
|
|
challengeType: 1
|
|
---
|
|
|
|
## Description
|
|
<section id='description'>
|
|
Searching is useful. However, you can make searching even more powerful when it also changes (or replaces) the text you match.
|
|
You can search and replace text in a string using <code>.replace()</code> on a string. The inputs for <code>.replace()</code> is first the regex pattern you want to search for. The second parameter is the string to replace the match or a function to do something.
|
|
|
|
```js
|
|
let wrongText = "The sky is silver.";
|
|
let silverRegex = /silver/;
|
|
wrongText.replace(silverRegex, "blue");
|
|
// Returns "The sky is blue."
|
|
```
|
|
|
|
You can also access capture groups in the replacement string with dollar signs (<code>$</code>).
|
|
|
|
```js
|
|
"Code Camp".replace(/(\w+)\s(\w+)/, '$2 $1');
|
|
// Returns "Camp Code"
|
|
```
|
|
|
|
</section>
|
|
|
|
## Instructions
|
|
<section id='instructions'>
|
|
Write a regex so that it will search for the string <code>"good"</code>. Then update the <code>replaceText</code> variable to replace <code>"good"</code> with <code>"okey-dokey"</code>.
|
|
</section>
|
|
|
|
## Tests
|
|
<section id='tests'>
|
|
|
|
```yml
|
|
tests:
|
|
- text: You should use <code>.replace()</code> to search and replace.
|
|
testString: assert(code.match(/\.replace\(.*\)/), 'You should use <code>.replace()</code> to search and replace.');
|
|
- text: Your regex should change <code>"This sandwich is good."</code> to <code>"This sandwich is okey-dokey."</code>
|
|
testString: assert(result == "This sandwich is okey-dokey." && replaceText === "okey-dokey", 'Your regex should change <code>"This sandwich is good."</code> to <code>"This sandwich is okey-dokey."</code>');
|
|
- text: You should not change the last line.
|
|
testString: assert(code.match(/result\s*=\s*huhText\.replace\(.*?\)/), 'You should not change the last line.');
|
|
|
|
```
|
|
|
|
</section>
|
|
|
|
## Challenge Seed
|
|
<section id='challengeSeed'>
|
|
|
|
<div id='js-seed'>
|
|
|
|
```js
|
|
let huhText = "This sandwich is good.";
|
|
let fixRegex = /change/; // Change this line
|
|
let replaceText = ""; // Change this line
|
|
let result = huhText.replace(fixRegex, replaceText);
|
|
```
|
|
|
|
</div>
|
|
|
|
|
|
|
|
</section>
|
|
|
|
## Solution
|
|
<section id='solution'>
|
|
|
|
```js
|
|
let huhText = "This sandwich is good.";
|
|
let fixRegex = /good/g; // Change this line
|
|
let replaceText = "okey-dokey"; // Change this line
|
|
let result = huhText.replace(fixRegex, replaceText);
|
|
```
|
|
</section>
|