CODEWITHSUNDEEP
phppreg-replace
ditto
ditto

Reputation: 6277

php: How to ignore letter case within a preg_replace?

I want to match text from a string, whilst ignoring it's letter case. My example fails if the letter cases are not identical.

/*
  $text:  fOoBaR
  $str:   little brown Foobar
  return: little brown <strong>Foobar</strong>
*/
function bold($text, $str) {
    // This fails to match if the letter cases are not the same
    // Note: I do not want to change the returned $str letter case.
    return preg_replace('/('.str_replace(array("/", "\\"), array("\/", "\\"), $text).')/', "<strong>$1</strong>", $str);
}

$phrase = [
    'little brown Foobar' => 'fOoBaR',
    'slash / slash' => 'h / sl',
    'spoon' => 'oO',
    'capital' => 'CAPITAL',
];

foreach($phrase as $str => $text)
    echo bold($text, $str) . '<br>';

Upvotes: 3

Views: 1874

Answers (2)

Cheery
Cheery

Reputation: 16214

Ok, a couple of modifications for the line

return preg_replace('/('.str_replace(array("/", "\\"), array("\/", "\\"), $text).
                     ')/', "<strong>$1</strong>", $str);

First, use modifier /i for the case-insensitive regexp.

Second, escape $text for the use in regexp as it might have symbols specific for the regexp (it also allows you to remove all those replacements that you have).

Third, no need in capturing the group, use the whole part of the string that fits the regexp by $0

return preg_replace('/'.preg_quote($text, '/').'/i','<strong>$0</strong>',$str);

Upvotes: 5

slapyo
slapyo

Reputation: 2991

Add the case insensitive modifier, i, to the regular expression.

function bold($text, $str) {
    // This fails to match if the letter cases are not the same
    // Note: I do not want to change the returned $str letter case.
    return preg_replace('/('.str_replace(array("/", "\\"), array("\/", "\\"), $text).')/i', "<strong>$1</strong>", $str);
}

Upvotes: 2

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