Favour str_replace() over ereg_replace() and preg_replace()

Speed tests show that str_replace() is 61% faster.
In terms of efficiency, str_replace() ¹⁰ is much more efficient than regular expressions at replacing strings. In fact, according to Making the Web, str_replace() is 61% more efficient than regular expressions like ereg_replace() ¹¹ and preg_replace() ¹².
If you’re using regular expressions, then ereg_replace() and preg_replace() will be much faster than str_replace().