string - PHP strtr vs str_replace benchmarking

Question

I'm curious what the most performant method of doing string transformations is. Given a n input string and a set of translations, what method is the most efficient in general? I currently use strtr(), but have tested various looping methods, str_replace() with an array, etc. The strtr() method benchmarks the fastest on my system, depending on the translations, but I'm curious if there are faster methods I haven't thought of yet.

If it's pertinent, my particular use case involves transforming 2-byte strings into ANSI color sequences for a terminal. Example:

// In practice, the number of translations is much greater than one...
$out = strtr("|rThis should be red", array('|r' => "33[31m"));

Answer 1

For simple replacements, strtr seems to be faster, but when you have complex replacements with many search strings, it appears that str_replace has the edge.