PHP characters limit 10 for display

<?php
echo substr(strip_tags("welcome to this new style editor for checking php code at online"), 2, 10);
?>

substr: Return "world" from the string: 
syntax: substr(string,start,length).

If the start parameter is a negative number and length is less than or equal to start, length becomes 0.

Parameter	Description
string	Required. Specifies the string to return a part of
start	Required. Specifies where to start in the string A positive number - Start at a specified position in the string A negative number - Start at a specified position from the end of the string 0 - Start at the first character in string
length	Optional. Specifies the length of the returned string. Default is to the end of the string. A positive number - The length to be returned from the start parameter Negative number - The length to be returned from the end of the string