81 lines
2.4 KiB
Markdown
81 lines
2.4 KiB
Markdown
|
---
|
||
|
|
title: Count occurrences of a substring
|
||
|
|
id: 596fda99c69f779975a1b67d
|
||
|
|
localeTitle: 596fda99c69f779975a1b67d
|
||
|
|
challengeType: 5
|
||
|
|
---
|
||
|
|
|
||
|
|
## Description
|
||
|
|
<section id='description'>
|
||
|
|
Tarea:
|
||
|
|
<p> Cree una función, o muestre una función incorporada, para contar el número de apariciones no superpuestas de una subcadena dentro de una cadena. </p><p> La función debe tomar dos argumentos: </p>
|
||
|
|
el primer argumento es la cadena a buscar, y
|
||
|
|
el segundo una subcadena a buscar.
|
||
|
|
<p> Debe devolver un número entero. </p>
|
||
|
|
<p> La coincidencia debe producir el mayor número de coincidencias no superpuestas. </p><p> En general, esto significa esencialmente hacer coincidir de izquierda a derecha o de derecha a izquierda. </p>
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Instructions
|
||
|
|
<section id='instructions'>
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Tests
|
||
|
|
<section id='tests'>
|
||
|
|
|
||
|
|
```yml
|
||
|
|
tests:
|
||
|
|
- text: <code>countSubstring</code> es una función.
|
||
|
|
testString: 'assert(typeof countSubstring === "function", "<code>countSubstring</code> is a function.");'
|
||
|
|
- text: ' <code>countSubstring("the three truths", "th")</code> debe devolver <code>3</code> '
|
||
|
|
testString: 'assert.equal(countSubstring(testCases[0], searchString[0]), results[0], "<code>countSubstring("the three truths", "th")</code> should return <code>3</code>.");'
|
||
|
|
- text: ' <code>countSubstring("ababababab", "abab")</code> debe devolver <code>2</code> '
|
||
|
|
testString: 'assert.equal(countSubstring(testCases[1], searchString[1]), results[1], "<code>countSubstring("ababababab", "abab")</code> should return <code>2</code>.");'
|
||
|
|
- text: ' <code>countSubstring("abaabba*bbaba*bbab", "a*b")</code> debe devolver <code>2</code> '
|
||
|
|
testString: 'assert.equal(countSubstring(testCases[2], searchString[2]), results[2], "<code>countSubstring("abaabba*bbaba*bbab", "a*b")</code> should return <code>2</code>.");'
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Challenge Seed
|
||
|
|
<section id='challengeSeed'>
|
||
|
|
|
||
|
|
<div id='js-seed'>
|
||
|
|
|
||
|
|
```js
|
||
|
|
function countSubstring (str, subStr) {
|
||
|
|
// Good luck!
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
### After Test
|
||
|
|
<div id='js-teardown'>
|
||
|
|
|
||
|
|
```js
|
||
|
|
console.info('after the test');
|
||
|
|
```
|
||
|
|
|
||
|
|
</div>
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Solution
|
||
|
|
<section id='solution'>
|
||
|
|
|
||
|
|
|
||
|
|
```js
|
||
|
|
function countSubstring(str, subStr) {
|
||
|
|
const escapedSubStr = subStr.replace(/[.+*?^$[\]{}()|/]/g, '\\$&');
|
||
|
|
const matches = str.match(new RegExp(escapedSubStr, 'g'));
|
||
|
|
return matches ? matches.length : 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
</section>
|