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  1. <?
  2. $repl="Г"; // "<span style='color:red'>Г</span>";
  3. $text = "аг бг вг гг";
  4. $RE1= "(?<=[абв])г";
  5. $RE2= "(?<=\\s[абв])г";
  6. $RE3= "(?<=\\s(?:а|б|в))г";
  7. echo preg_replace("/$RE1/", $repl, $text); // ok
  8. echo "\n";
  9. echo preg_replace("/$RE2/", $repl, $text); // fail, expected аг бГ вГ гг
  10. echo "\n";
  11. echo preg_replace("/$RE3/", $repl, $text); // ok
  12. ?>
Success #stdin #stdout 0.01s 20520KB
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аГ бГ вГ гг
аг бг вг гг
аг бГ вГ гг
https://ideone.com/fdOelO
language:
PHP (php 7.3.5)
created:
11 years ago
visibility:
secret

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