从包含php的字符串中获取X字符

Question

I have a PHP problem where I have a string of numbers:

ie/ 1,2,3,4,5,6,7,8,9...... X

I know the first number and have to create a string X long so that it wraps around

for example if my string is 1,2,3,4,5 and my first number is 4 - i need to return the string:

4,5,1,2,3

I'd like to create a function to achieve this - any help would be great!

Thanks.

Answer 1

<?php
function MyWrap($string, $first)
{
    $splitHere = strpos($string, $first);
    return rtrim(substr($string, $splitHere).','.substr($string, 0, $splitHere), ',');
}

echo MyWrap('1,2,3,4,5', '4');
?>

Output:

4,5,1,2,3