<?php
 
error_reporting(-1);
 
// Задача: подставить переменные в строку
$data = array(
	'name'		=>	'Ivan',
	'phrase'	=>	'Hello World!'
);
 
$format = "{name} says: {phrase}\n";
 
$result = preg_replace_callback("/\\{([a-zA-Z_]+)\\}/", function ($m) use ($data) {
 
	$key = $m[1];
	if (isset($data[$key])) {
		return $data[$key];
	}
 
	throw new Exception("Inavlid placeholder: '{$m[0]}'");
 
}, $format);
 
echo $result;

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