Example:
$strSubstitutor = new StrSubstitutor(array('NAME' => 'John', 'SURNAME' => 'Smith'));
$substituted = $strSubstitutor->replace('Hi, {{NAME}} {{SURNAME}}');
Result:
Hi, John Smith
Example:
$strSubstitutor = new StrSubstitutor(array(), 'Unknown');
$substituted = $strSubstitutor->replace('Hi, {{NAME}}');
Result:
Hi, Unknown