I am trying to grab the capital letters of a couple of words and wrap them in span tags. I am using preg_replace for extract and wrapping purposes, but it's not outputting anything.
preg_replace("/[A-Z]/", "<span class=\"initial\">$1</span>", $str)
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Andy Lester
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Polsonby
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4 Answers
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You need to put the pattern in parentheses /([A-Z])/, like this:
preg_replace("/([A-Z])/", "<span class=\"initial\">$1</span>", $str)
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8@Gumbo: Answering your own questions is perfectly fine, even encouraged, as long as the question isn't a duplicate of another one on the site. – Bill the Lizard Jun 23 '09 at 18:00
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The `$1` bit in the replacement string is what I was needing. Thanks! – rinogo Dec 20 '19 at 18:05
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\0 will also match the entire matched expression without doing an explicit capture using parenthesis.
preg_replace("/[A-Z]/", "<span class=\"initial\">\\0</span>", $str)
As always, you can go to php.net/preg_replace or php.net/<whatever search term> to search the documentation quickly. Quoth the documentation:
\0 or $0 refers to the text matched by the whole pattern.
HamZa
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John Douthat
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From the preg_replace documentation on php.net:
replacement may contain references of the form \n or (since PHP 4.0.4) $n, with the latter form being the preferred one. Every such reference will be replaced by the text captured by the n'th parenthesized pattern.
See Flubba's example.
Wedge
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