PHP trim / rtrim / ltrim VS正则表达式

I tend to use rtrim, ltrim and trim to strip off spaces at the end, left or right. I also use them to strip off the characters at the end or the beginning of the string. Is it faster than a regular expression? Is there anything wrong with the following code?

 $string = " hello: ";
 $string = rtrim(trim($string), ":"); //hello 

Would it make any difference if I were to use a regular expression in terms of performance?

Regular expressions usually make things slower, especially applied to such small strings, due to the expression analysis overhead.

Assuming that a colon would never appear on the left side, you could eliminate the rtrim():

$string = trim($string, ": "); // trim either space or colon on either side