Search and replace random word - php

Question

well, first of all let me say, before posting this I've tested many things, many time, but currently, I don't actually know what else to do, because nothing works fine for me.
This is the code I have currently:
<?php
// These are the arrays given by the application. All of them has an "%s" within.
// For example...
$arrs = array(
"this is a %s array" => "converted1 %s text",
"value %s test" => "converted2 %s text",
"test %s test" => "converted3 %s text"
);
$text = "This is a random text. Which can contains or not some of the expressions listed above. In this case it contains this: this is a magic array, value hey test, test php test";
// The output should be:
// "This is a random text. Which can contains or not some of the expressions listed above. In this case it contains this: CONVERTED magic TEXT, CONVERTED2 hey TEXT, CONVERTED3 php TEXT"
foreach($arrs as $k => $v){
// Seriously, I don't know what's next here... also I'm thinking this foreach is not right here.
}
?>
The main objective, is to write something random in a textbox input. So I check within the textbox if some of the array keys ($arrs) has been filled in. The problem, is that I can not detect it using strpos, due %s will be always random, so it's a bit harder to find its position...
Let's say I write "this is a random array" (it is into the array), so if we check its value, we'll see it would be "converted1 RANDOM text".
I've tested for using patterns, also with explode();, and preg_replace_callback, and nothing works for me. This is really driving me crazy...
Thank you very much guys.

Answer 1

Use regular expression.
<?php
$pattern = '~this is a ([^ ]*) array~U';
$replace = 'converted1 $1 text';
$text = preg_replace($pattern,$replace,$text);
you have assoc array already, you can change keys to be regular expressions and values to replace strings (with escaped group like $1 above). Also within foreach() you can check first:
<?php
if (preg_match($k,$text)) {
// do the replacing here
}
Note:
I've used [^ ]* to match single word. It's not only way, it may not be the best way. You can also use \w, but I personally don't like it :)
Edit:
Here you go with ready code that works (just tested it on my XAMPP)
<?php
$arrs = array(
"~this is a ([^ ]*) array~U" => "converted1 $1 text",
"~value ([^ ]*) test~U" => "converted2 $1 text",
"~test ([^ ]*) test~U" => "converted3 $1 text"
);
$text = "This is a random text. Which can contains or not some of the expressions listed above. In this case it contains this: this is a magic array, value hey test, test php test";
foreach($arrs as $k => $v){
if (preg_match($k,$text)) {
$text = preg_replace($k,$v,$text);
}
}
?>