freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-an.../basic-algorithm-scripting/repeat-a-string-repeat-a-st...

81 lines
2.3 KiB
Markdown
Raw Normal View History

---
id: afcc8d540bea9ea2669306b6
title: Repeat a String Repeat a String
isRequired: true
challengeType: 5
forumTopicId: 16041
---
## Description
<section id='description'>
Repeat a given string <code>str</code> (first argument) for <code>num</code> times (second argument). Return an empty string if <code>num</code> is not a positive number.
Remember to use <a href="https://www.freecodecamp.org/forum/t/how-to-get-help-when-you-are-stuck-coding/19514" target="_blank">Read-Search-Ask</a> if you get stuck. Write your own code.
</section>
## Instructions
<section id='instructions'>
</section>
## Tests
<section id='tests'>
```yml
tests:
- text: <code>repeatStringNumTimes("*", 3)</code> should return <code>"***"</code>.
testString: assert(repeatStringNumTimes("*", 3) === "***");
- text: <code>repeatStringNumTimes("abc", 3)</code> should return <code>"abcabcabc"</code>.
testString: assert(repeatStringNumTimes("abc", 3) === "abcabcabc");
- text: <code>repeatStringNumTimes("abc", 4)</code> should return <code>"abcabcabcabc"</code>.
testString: assert(repeatStringNumTimes("abc", 4) === "abcabcabcabc");
- text: <code>repeatStringNumTimes("abc", 1)</code> should return <code>"abc"</code>.
testString: assert(repeatStringNumTimes("abc", 1) === "abc");
- text: <code>repeatStringNumTimes("*", 8)</code> should return <code>"********"</code>.
testString: assert(repeatStringNumTimes("*", 8) === "********");
- text: <code>repeatStringNumTimes("abc", -2)</code> should return <code>""</code>.
testString: assert(repeatStringNumTimes("abc", -2) === "");
- text: The built-in <code>repeat()</code> method should not be used.
testString: assert(!/\.repeat/g.test(code));
- text: <code>repeatStringNumTimes("abc", 0)</code> should return <code>""</code>.
testString: assert(repeatStringNumTimes("abc", 0) === "");
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='js-seed'>
```js
function repeatStringNumTimes(str, num) {
// repeat after me
return str;
}
repeatStringNumTimes("abc", 3);
```
</div>
</section>
## Solution
<section id='solution'>
```js
function repeatStringNumTimes(str, num) {
if (num < 1) return '';
return num === 1 ? str : str + repeatStringNumTimes(str, num-1);
}
repeatStringNumTimes("abc", 3);
```
</section>