Replace consecutive numbers by first numbers in a string with Regex/PHP

Question

I have that string : $text=70ac0f2e7247e9a658f71fe6362bf53

I want to replace all consecutive numbers by only the first number. For example I want to replace 70 by 7, 7247 by 7, 658 by 6 and so on.

I have this pattern : $pattern = '/[0-9]{2,}/'; but I don't know how I could build the $replacement and the preg_replace to make :

preg_replace ($pattern2,$replacement,$text3);

Thank you !

revo · Accepted Answer · 2017-09-14 15:18:09Z

1

Turning my comment into an answer, you need to use a capturing group:

preg_replace('/([0-9])[0-9]*/', '$1', $text3);

or like what @chris85 said you may go with a match resetter \K:

preg_replace('/[0-9]\K[0-9]*/', '', $text3);

answered Sep 14, 2017 at 15:18

revo

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Comments

mickmackusa · Accepted Answer · 2024-08-14 07:29:02Z

0

It doesn't make any sense to replace an empty string with an empty string, so only perform a replacement if consecutive numbers are encountered.

Code: (Demo)

$text = '70ac0f2e7247e9a658f71fe6362bf53';

echo preg_replace('#\d\K\d+#', '', $text);
// 7ac0f2e7e9a6f7fe6bf5

answered Aug 14, 2024 at 7:29

mickmackusa♦

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