使用变量内部变量

I have following scenario.I am creating a config page where I set the format in one place. I am using this format in more than 10 php pages.

//Settings

$format = "$one $two $three";
$one = 1;
$two = 2;
$three = 3;
echo $format;

//This should output 1 2 3

Right now if I want to change the format I need to change "$two $one $three" in all 10 pages ,, how can I set this in one place and reuse it in multiple place.Is this possible in php ?

P.s :

My scenario : I have settings.php , where I set $format = "$one $two $three"; , I am including settings.php in all 10 pages.... When I change $format in settings.php it should should be reflected in all 10 pages..without much work.

You should write a function which creates the format according to your needs:

function createFormat($one, $two, $three)
{
    return "$one $two $three";
}

Then, whereever you need the format, you just write:

$format = createFormat($one, $two, $three);

You can use an callable do it better (in settings.php):

//define the function first, with references
$one = 0; $two = 0; $three = 0;
$format = function () use (&$one,&$two,&$three) { print "$one $two $three";};

In the next file you do

$one = 1; $two = 2; $three = 3;
$format();//will print "1 2 3"
$one = 2; $two = 5; $three = 6;
$format();//will print "2 5 6"

This can work, but you have to keep an eye on the used references (variables)

inline variable parsing:

    $one=1; $two=2; $three=3;  
    $format = "{$one} {$two} {$three}";  
    return $format;