我如何使用正则表达式比较php字符串变量

Question

I would like to match (with regex) two strings ignoring the fact that one string may or may not have hyphens and/or single-quote chars (in fact just ignore all punctuation in both strings).

The problem is both strings are within PHP variables, not literals which i can do easily however, but not with variables - any ideas please ... is this even possible.

For example like a pattern modifier /i which specifies case-insensitive comparisons - is there a modifier to say ignore punctuation just compare alpha-numeric strings ??

Answer 1

if (preg_replace("/['\-]/", '', $str1) == preg_replace("/['\-]/", '', $str2) {
   ...equal...
}

basically: strip out ' and - from both strings, then compare the resulting stripped strings. If yout want case-insensitive, then do strtolower(preg_replace(....)) instead.

Answer 2

I am replacing all the non-alphanumeric + Space( \\s ) characters from the both strings. Then using one string inside the regex to match against other one.

$str1 = "alexander. was a hero!!";
$str2 = "alexander, was a hero?";
if(preg_match(
        "/^".preg_replace("/[^a-zA-Z0-9\s]/", "", $str1)."$/i", 
        preg_replace("/[^a-zA-Z0-9\s]/", "", $str2)
    )){
    print "matched!";
}

If you want, you may ignore the space( \\s ) from the above regex.