As per this thread it's pretty easy to remove all digits from a string in PHP.
For example:
$no_digits = preg_replace('/\d/', '', 'This string contains digits! 1234');
But, I don't want digits removed that are part of HTML charactr codes such as:
)
©
How can I get Regex to ignore numbers that are part of a HTML character code? i.e. numbers that are sandwiched between &# and ; characters?
You can use (*SKIP)(*F) verb:
echo preg_replace('/&#\d+;(*SKIP)(*F)|\d+/', '',
'This string contains digits! 1234 ) © 5678');
//=> This string contains digits! ) ©
&#\d+;(*SKIP)(*F) will skip the match id regex matches &#\d+; pattern.
Alternatively you can use lookarounds:
echo preg_replace('/(?<!&#)\d+|\d+(?!;)/', '',
'This string contains digits! 1234 ) © 5678');
Which means match 1 or digits that are either not preceded by &# OR not followed by ; thus making it skip &#\d+; pattern.
You can use
var output = Regex.Replace(input, @"[\d-]", string.Empty);
***The \d identifier simply matches any digit character.
\d only matches 0-9, single digit, need a quantifier for tens/hunderds/thousands/etc.As an option, you could convert your code to UTF-8 encoding (if it’s not already UTF-8), then convert HTML entities to corresponding characters with html_entity_decode(), then remove numbers with a regexp, then, if needed, convert special characters to corresponding entities again with htmlentities() (in UTF-8, it’s actually enough to escape just a minimal subset of special characters via htmlspecialchars()), then convert code back to your original encoding (if the original string was not in UTF-8).
You can use look behind and look ahead.
$no_digits = preg_replace('/(?<!&#)\d+(?=[^;\d])/', '', 'This string contains ) digits! 1234');
So basically, (?<!&#) tells RegEx to look behind \d+ to make sure that there is no &# and (?=[^;\d]) tells RegEx to look ahead of \d+ to make sure that it is not a semicolon or a number.
I like this solution a bit better as it can be used on most RegEx like in Java and JavaScript.
Hope this helps.
Edit: miss one character <.
\d. Once found, it looks behind to see if it is not &# then it will trigger \d found. It is a relative thing. :-p
<. Cheers.
'~(?i:[&%](?:[a-z]+|(?:\#(?:[0-9]+|x[0-9a-f]+)));(*SKIP)(*FAIL)|\d+)~'