Replace curly braced placeholders with values from a lookup array

Question

I would like to know if there is a simple way to use the matched pattern in a `preg_replace` as an index for the replacement value array. e.g. ``` preg_replace("/\{[a-z_]*\}/i", "{$data_array[\1]}", $string); ``` Search for a placeholder like `{xxx}` and replace it with the value in `$data_array['xxx']`, where `xxx` is the matched text inside the curly braces. But this expression does not work as it's invalid php. I have written the following function, but I'd like to know if it is possible to do it simply. I could use a callback, but how would I pass the `$data_array` to it too? ``` function mailmerge($string, $data_array, $tags='{}') { $tag_start=$tags[0]; $tag_end =$tags[1]; if( (!stristr($string, $tag_start)) && (!stristr($string, $tag_end)) ) return $string; while(list($key,$value)=each($data_array)) { $patterns[$key]="/".preg_quote($tag_start.$key.$tag_end)."/"; } ksort($patterns); ksort($data_array); return preg_replace($patterns, $data_array, $string); } ```

Accepted Answer

From my head:

```
preg_replace_callback("/\{([a-z_]*)\}/i", function($m) use($data_array){
  return $data_array[$m[1]];
}, $string);
```

Note: The above function requires PHP 5.3+.

Replace curly braced placeholders with values from a lookup array

Solution

Problem