PHP to remove all non-alphanum characters between two strings

Question

I need to remove non-alphanumeric characters from between two strings using PHP.

Input:

name="K9 Mk. II"

built=2015.06.15

name="Queen Eliz. 3rd (HRH)"

Expected output:

name="K9MkII"

built=2015.06.15

name="QueenEliz3rdHRH"

My code:

$contents = file_get_contents("input.txt");
$contents = preg_replace('/name=\"[^A-Za-z0-9]\"/', "name=\"\\1\"", $contents);

Edit: it should only remove unwanted characters from between name=" and ". The line containing built=2015.06.15 should remain unchanged.

As always, your help is greatly appreciated.

WtS

Answer 1

Use preg_replace_callback:

$arr = array('name="K9 Mk. II"','name="Queen Eliz. 3rd (HRH)"');
foreach($arr as $str) {
    $str = preg_replace_callback('/(?<=name=")([^"]+)(?=")/',
        function ($m) {
            return preg_replace("/\W+/", "", $m[1]);
        },
        $str);
    echo $str,"\n";
}

Output:

name="K9MkII"
name="QueenEliz3rdHRH"

Answer 2

Here is the pattern you're looking for -

[^name=\w\"]

This excludes 'name=', word characters and whitespace. See it in action here

You can also use the return value instead of actual replacement -

$content = preg_replace('/[^name=\w\"]/', '$1', $content);

As the '$1' will retain the quotes as you need them.

Answer 3

You can use PHP's preg_replace_callback() to first match the names by using: /name="([a-z0-9]+)"/i and then calling a function removing the spaces in each match.

Answer 4

$output = preg_replace('/[^\da-z]/i', '', $InputString);

here i means case-insensitive.

$InputString is the input you provide.
$output contains the result we want