Php str_replace - two values to replace?

问题:

Using str_replace I want to change $url from this:

$url = http://example.com/images/lala1.jpg

to this

$url = http://example.com/images/lala1-0001.jpg

My problem is that I don't know how to insert the "-".

$url is changing so I really only know that it has ".jpg" at its' end.

My code so far:

for($i=1;$i<=9;$i++) {
    $array[] = str_replace('.jpg',sprintf("%04d",$i).'.jpg',$url); }

Any idea how I can make this work?

回答1:

Sprintf allows for regular characters in the arguments:

str_replace('.jpg', sprintf("-%04d.jpg", $i), $url);

回答2:

You might want to make use of a regular expression:

$str = preg_replace('/\.jpg$/', sprintf("-%04d.jpg",$i), $url);

This insures that it ONLY gets replaced at the end of the string.