Using str_replace so that it only acts on the first match?

Question

I want a version of str_replace() that only replaces the first occurrence of $search in the $subject. Is there an easy solution to thi

Answer 1

According to my test result, I'd like to vote the regular_express one provided by karim79. (I don't have enough reputation to vote it now!)

The solution from zombat uses too many function calls, I even simplify the codes. I'm using PHP 5.4 to run both solutions for 100,000 times, and here's the result:

$str = 'Hello abc, have a nice day abc! abc!';
$pos = strpos($str, 'abc');
$str = substr_replace($str, '123', $pos, 3);

==> 1.85 sec

$str = 'Hello abc, have a nice day abc! abc!';
$str = preg_replace('/abc/', '123', $str, 1);

==> 1.35 sec

As you can see. The performance of preg_replace is not so bad as many people think. So I'd suggest the classy solution if your regular express is not complicated.