Replace literal string in text if another literal string doesn't exist in the text [closed]

Question

Closed. This question needs details or clarity. It is not currently accepting answers.

Want to improve this question? As written, this question is lacking some of the information it needs to be answered. If the author adds details in comments, consider editing them into the question. Once there's sufficient detail to answer, vote to reopen the question.

Closed last year.

Improve this question

I have these 3 strings:

$string = "his";
$str1 = "hi";
$str2 = "s";

So what I want to do is a regex that looks for hi and replaces it. But! if there is s in the string it won't be replaced. Like this.

preg_replace('/'.$str1.'^['.$str2.']/', "replace it with this", $string);

It's not working! (of course not, regex isn't my thing!)

As I said, I don't get this with regex. I want to find $str1 and if $str2 isn't in the string it won't be replaced.

First: This is a good tutorial: regular-expressions.info/tutorialcnt.html - If you have specific points where you're getting stuck, ask a specific question about that point. — Amadan
– Amadan, Commented Jan 29, 2013 at 2:09
I really love RegexBuddy. Use it to build, explain, test and debug regular expressions. — Arnold Daniels
– Arnold Daniels, Commented Jan 29, 2013 at 2:14

zerkms · Accepted Answer · 2013-01-29 02:06:51Z

2

$str = 'his';

$s1 = 'hi';
$s2 = 's';

$result = preg_replace('~' . preg_quote($s1) . '(?!' . preg_quote($s2) . ')~', 'replace with this', $str);
                      // ~hi(?!s)~
                      // this regex means:
                      //   "hi" string followed by anything but "s"

var_dump($result);

Live examples:

answered Jan 29, 2013 at 2:06

zerkms

256k73 gold badges447 silver badges551 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Kilise Over a year ago

Whatif i want to do exactly as I said but by using arrays? preg_replace ($arr.(?! $arr2,$replacewitharray ,$instring) (just fast example)

zerkms Over a year ago

@Kilise: what do you want to achieve? Regular expression is always a string. Your question looks like "what I want to do the same but by using orange"

Kerem · Accepted Answer · 2013-01-29 04:18:35Z

0

I think you want to make multiple filters, like: s,m etc or more..

$s = array('s', 'm');
$result = preg_replace('~hi(?!'. join('|', $s) .')~', 'replace with this', 'him');
print $result; // him
// and
$result = preg_replace('~hi(?!'. join('|', $s) .')~', 'replace with this', 'hiz');
print $result; // replace with thisz

answered Jan 29, 2013 at 4:18

Kerem

11.6k5 gold badges61 silver badges58 bronze badges

Collectives™ on Stack Overflow

Replace literal string in text if another literal string doesn't exist in the text [closed]

2 Answers 2

2 Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Related