Question

I know there are lots of tutorials and question on replacing something in a string.

But I can’t find a single one on what I want to do!

Lets say I have a string like this

$string="Hi! [num:0]";

And an example array like this

$array=array();
$array[0]=array('name'=>"na");
$array[1]=array('name'=>"nam");

Now what I want is that PHP should first search for the pattern like [num:x] where x is a valid key from the array.
And then replace it with the matching key of the array. For example, the string given above should become: Hi! na

I was thinking of doing this way:

1. Search for the pattern.
2. If found, call a function which checks if the number is valid or not.
3. If valid, returns the name from the array of that key like 0 or 1 etc.
4. PHP replaces the value returned from the function in the string in place of the pattern.

But I can’t find a way to execute the idea. How do I match that pattern and call the function for every match?

This is just the way that I am thinking to do. Any other method will also work.

If you have any doubts about my question, please ask in comments.

Answer 1

Try this

$string="Hi! [num:0]";
$array=array();
$array[0]=array('name'=>"na");
$array[1]=array('name'=>"nam");


echo preg_replace('#(\!)?\s+\[num:(\d+)\]#ie','isset($array[\2]) ? "\1 ".$array[\2]["name"] : " "',$string);