Php preg_replace_callback no work me - php

Question

I try replace characters from string and put others , for this use preg_replace_callback function , the problem is this function change order of original text and show differents results
For example if the string it´s :
Hello everybody [1-2-3] this it´s one test [4-5-6-7-8] --- > ORIGINAL TEXT
The script search the [ ] and separate this content with [ ] from the other text , but show me as i put here :
1-2-3 4-5-6-7-8 Hello Everybody this it´s one test --- > BAD RESULT
When the right order it´s the first without [ ]
Hello everybody 1-2-3 this it´s one test 4-5-6-7-8
The script i create :
<?php
$text = " This is a test [gal~ruta~100~100] This is other test [gal~ruta2~100~100]";
function gal($matches)
{
global $text;
$exp=explode("~",$matches[1]);
$end=str_replace($matches[1],$a,$text);
if ($exp[0]=="gal")
{
$a="".$exp[1]."".$exp[2]."".$exp[3]."";
echo $a;
}
}
echo preg_replace_callback(
"/\[(.*?)\]/",
"gal",
$text);
?>
Thank´s everybody for the help

Answer 1

You need to return something from your callback, which will be substituted in the original string. You most certainly don't want to echo, which will send the values straight to the output, in order of execution.
However, it sounds like you don't even need a callback function to remove the brackets around your numbers.
$str = preg_replace("/\[(.*?)\]/", "$1", $str);
CodePad.