Write a PHP script to insert a string at the specified position in a given string

PHP is a server scripting language, and It is a powerful tool for making interactive and dynamic Web-pages. I have used WampServer 2.2 for following example..

<?php
$originalstring = 'tech- The Complete Debugging Solution';
$stringtoinsert ='study.org';
$insertpos = 4;
$newstring = substr_replace($originalstring, $stringtoinsert.' ', $insertpos, 0);
echo $newstring."\n";
?>

Result:

techstudy.org - The Complete Debugging Solution