Replace overlapping strings in php

Question

I need to replace a huge amount of words and phrases in long strings, words and phrases might repeat several times.

I have successfully built a preg_replace() arrays and it works nearly well. The only problem is that the list of words and phrases to replace I want to have is overlapping, for example:

"acid" ---> "replacement1"

"light acid" --> "replacement2"

and it makes preg_replace to complain, as "acid" is in both, which is not surprising.

The question: How to build a proper function to replace words and phrases like in my scenario?

Why don't you use [`str_replace()`](http://php.net/str_replace) then? — Darren, Apr 13 '15 at 06:31
Presort the replacement patterns by their length and apply them downwards? — arkascha, Apr 13 '15 at 06:31
@arkascha Why not making an answer out of it? Then the question wouldn't stay open. — hek2mgl, Apr 13 '15 at 08:12

arkascha · Accepted Answer · 2015-04-13T08:32:18.663

1

Just presort the replacement patterns by their length and apply them downwards. That way longer strings will get replaced first. Therefore any contained substring in there cannot be replaced accidentally by other, shorter replacement rules.

edited Apr 13 '15 at 08:32

answered Apr 13 '15 at 08:22

arkascha

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An example would be nice ;) – hek2mgl Apr 13 '15 at 08:27
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@hek2mgl an example of sorting something by length? Come on... no code in the question => no code in the answer. – arkascha Apr 13 '15 at 08:30
Thanks, it is exactly what I missed in my logic, thanks, mate :) – jerome Apr 14 '15 at 07:19

Replace overlapping strings in php

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