Question

I have a doubt again on RegEx in Php.

Assume that I have a line like this

716/52  ; 250/491.1; 356/398; 382/144

I want the output to be

1. Replace all semi-colon with comma. I think I can do this using

   $myline= str_replace(";", ",", $myline);
   

2. Interchange the numbers and replace ‘/’ with a comma. That is, 716/52 will become 52,716. This is where I get stuck.

So, the output should be

52,716 , 491.1,250, 398,356, 144,382

I know that using sed, I can achieve it as

1,$s/^classcode:[\t ]\+\([0-9]\+\)\/\([0-9]\+\)/classcode: \2\,\1/

But, how do I do it using preg_match in php?

Answer 1

$str = '716/52  ; 250/491.1; 356/398; 382/144';

$str = str_replace(';', ',', $str);

$res = preg_replace_callback('~[\d.]+/[\d.]+~', 'reverse', $str);

function reverse($matches)
{
    $parts = explode('/', $matches[0]);
    return $parts[1] . ',' . $parts[0];
}

var_dump($res);

And working sample: http://ideone.com/BeS9j

UPD: PHP 5.3 version with anonymous functions

$str = '716/52  ; 250/491.1; 356/398; 382/144';

$str = str_replace(';', ',', $str);

$res = preg_replace_callback('~[\d.]+/[\d.]+~', function ($matches) {
    $parts = explode('/', $matches[0]);
    return $parts[1] . ',' . $parts[0];
}, $str);

var_dump($res);