formating data in php

Question

What I need to be able do is format data in a variable, like so:

format: xxx-xxx variable: 123456 output: 123-456

The problem is I need to be able to change the format, so a static solution wouldn't work. I also like to be able to change the variable size, like:

format: xxx-xxx variable: 1234 output: 1-234

All ideas are welcome! Thanks for your help!

Note: All of the variables will be numbers

Edit I should have been clear on the format its not going to always be grouping of 3, and it may have more then "-" as a symbol, the groups will be inconstant 1-22-333-4444 it will only be in grouping of 1-5

Answer 1

Your best bet is preg_replace.

Regular expressions take some getting used to, but this is probably your best bet...

EDIT:

//initial parsing
$val = preg_replace(
    '/(\d*?)(\d{1,2}?)(\d{1,3}?)(\d{1,4})$/', 
    '${1}-${2}-$[3}-${4}', 
    $inputString
);

//nuke leading dashes
$val - preg_replace('^\-+', '', $val);

The key is to make every set, except the righ-most one non-greedy, allowing for a right-side oriented pattern match.

Answer 2

You could implement the strategy pattern and and have new formatting classes that are swappable at run time. It looks complicated if you haven't seen it before but it really helps with maintainability and allows you to switch the formatter with the setFormatter() at any time.

class StyleOne_Formatter implements Formatter
{
    public function format($text)
    {
      return substr($text,0,3).'-'.substr($text,3);
    }
}

class StyleTwo_Formatter implements Formatter
{
    public function format($text)
    {
      return substr($text,0,1).'-'.substr($text,1);
    }
}

Then you would have your formatting class which would be like so:

class NumberFormatter implements Formatter
{

   protected $_formatter = null;

   public function setFormatter(Formatter $formatter)
   {
      $this->_formatter = $formatter;
   }

   public function format($text)
   {
     return $this->_formatter->format($text);
   }
}

Then you could use it like this:

 $text = "12345678910";
 $formatter = new NumberFormatter();

 $formatter->setFormatter(new StyleOne_Formatter());
 print $formatter->format($text);
 // Outputs 123-45678910

 $formatter->setFormatter(new StyleTwo_Formatter());
 print $formatter->format($text);
 // Outputs 1-2345678910

Answer 3

If the input you are formatting is always an integer you can try number_format and format as money (thousands etc..) Here is a solution which takes any string and turns it into your desired format:

$split_position = 3;
$my_string      = '';
echo strrev(implode('-',(str_split(strrev($my_string),$split_position))));

input: 1234;     output: 1-234
input: abcdefab; output: ab-cde-fab
input: 1234567   output: 1-234-567