93 lines
1.9 KiB
Markdown
93 lines
1.9 KiB
Markdown
---
|
|
id: 587d7db9367417b2b2512ba7
|
|
title: Specify Exact Number of Matches
|
|
challengeType: 1
|
|
forumTopicId: 301365
|
|
dashedName: specify-exact-number-of-matches
|
|
---
|
|
|
|
# --description--
|
|
|
|
You can specify the lower and upper number of patterns with quantity specifiers using curly brackets. Sometimes you only want a specific number of matches.
|
|
|
|
To specify a certain number of patterns, just have that one number between the curly brackets.
|
|
|
|
For example, to match only the word `hah` with the letter `a` `3` times, your regex would be `/ha{3}h/`.
|
|
|
|
```js
|
|
let A4 = "haaaah";
|
|
let A3 = "haaah";
|
|
let A100 = "h" + "a".repeat(100) + "h";
|
|
let multipleHA = /ha{3}h/;
|
|
multipleHA.test(A4);
|
|
multipleHA.test(A3);
|
|
multipleHA.test(A100);
|
|
```
|
|
|
|
In order, the three `test` calls would return `false`, `true`, and `false`.
|
|
|
|
# --instructions--
|
|
|
|
Change the regex `timRegex` to match the word `Timber` only when it has four letter `m`'s.
|
|
|
|
# --hints--
|
|
|
|
Your regex should use curly brackets.
|
|
|
|
```js
|
|
assert(timRegex.source.match(/{.*?}/).length > 0);
|
|
```
|
|
|
|
Your regex should not match the string `Timber`
|
|
|
|
```js
|
|
timRegex.lastIndex = 0;
|
|
assert(!timRegex.test('Timber'));
|
|
```
|
|
|
|
Your regex should not match the string `Timmber`
|
|
|
|
```js
|
|
timRegex.lastIndex = 0;
|
|
assert(!timRegex.test('Timmber'));
|
|
```
|
|
|
|
Your regex should not match the string `Timmmber`
|
|
|
|
```js
|
|
timRegex.lastIndex = 0;
|
|
assert(!timRegex.test('Timmmber'));
|
|
```
|
|
|
|
Your regex should match the string `Timmmmber`
|
|
|
|
```js
|
|
timRegex.lastIndex = 0;
|
|
assert(timRegex.test('Timmmmber'));
|
|
```
|
|
|
|
Your regex should not match the string `Timber` with 30 `m`'s in it.
|
|
|
|
```js
|
|
timRegex.lastIndex = 0;
|
|
assert(!timRegex.test('Ti' + 'm'.repeat(30) + 'ber'));
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --seed-contents--
|
|
|
|
```js
|
|
let timStr = "Timmmmber";
|
|
let timRegex = /change/; // Change this line
|
|
let result = timRegex.test(timStr);
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```js
|
|
let timStr = "Timmmmber";
|
|
let timRegex = /Tim{4}ber/; // Change this line
|
|
let result = timRegex.test(timStr);
|
|
```
|