How do I find repeated characters using a regular expression? If I have <code>aaabbab</code>, I would like to match only characters which have three repetitions: <pre class="prettyprint"><code>aaa </code></pre>

Try <code>string.scan(/((.)\2{2,})/).map(&:first)</code>, where <code>string</code> is your string of characters. The way this works is that it looks for any character and captures it (the dot), then matches repeats of that character (the <code>\2</code> backreference) 2 or more times (the <code>{2,}</code> range means "anywhere between 2 and infinity times"). Scan will return an array of arrays, so we map the first matches out of it to get the desired results.

How do I match repeated characters?

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ruby

How do I find repeated characters using a regular expression?

If I have aaabbab, I would like to match only characters which have three repetitions:

aaa

949

asked Dec 27 '22 08:12

loganathan

1 Answers

Try string.scan(/((.)\2{2,})/).map(&:first), where string is your string of characters.

The way this works is that it looks for any character and captures it (the dot), then matches repeats of that character (the \2 backreference) 2 or more times (the {2,} range means "anywhere between 2 and infinity times"). Scan will return an array of arrays, so we map the first matches out of it to get the desired results.

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