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phpregexpcreemoticons

Replace :D emoticons, except inside ":D"

I have:

$txt = ':D :D ":D" :D:D:D:D';

I want to preg_replace all :D to ^ and if ":D" then not replace.

===> output: '^ ^ ":D" ^^^^';
Solution

  • (*SKIP)(*F) Magic

    $replaced = preg_replace('~"[^"]+"(*SKIP)(*F)|:D~', '^', $yourstring);

    In the demo, see the substitutions in the bottom pane.

    This problem is a classic case of the technique explained in this question to "regex-match a pattern, excluding..."

    The left side of the alternation | matches complete "quotes" then deliberately fails, after which the engine skips to the next position in the string. So the quotes are neutralized. The right side matches :D, and we know they are the right ones because they were not matched by the expression on the left.

    Reference