Not sure about the order of code and the tags are correct but:
Assuming you converted your JSON string to a JSON object, yes you can.
In PHP you have a couple of choices:
Either you continue with your $currentProject as a STDClass Object or you convert it into an array:
// STDClass Object (Access with 'STDObject->key' returns value)
$currentProduct = json_decode($json_string); // Converts to STDClass Object
// Array Object (Access with Array[key] returns value)
$currentProduct = json_decode($json_string, true); // Converts to Array Object
With and STDClass Object:
1:
// Use '{' and '}' to specify the interpreter you're dealing with an object.
$pageTitle = "Company Name | Our Products - {$currentProduct->title}"; // assuming $currentProduct is a String at least
2:
// Using ' single quotes with this case is better
// but you can't put the variable inside it. (Not that you need it in this case)
$pageTitle = 'Company Name | Our Products - '.$currentProduct->title; // Concatenate the string
3:
String Operators documentation
$pageTitle .= $currentProduct->title;
And now the same but with an Array Object:
1:
// Use '{' and '}' to specify the interpreter you're dealing with an object.
$pageTitle = "Company Name | Our Products - {$currentProduct['title']}"; // assuming $currentProduct is a String at least
2:
// Using ' single quotes with this case is better
// but you can't put the variable inside it. (Not that you need it in this case)
$pageTitle = 'Company Name | Our Products - '.$currentProduct['title']; // Concatenate the string
3:
String Operators documentation
$pageTitle .= $currentProduct['title'];
Note:
For the PHP Interpreter to —take in consideration— variables inside a string you must use " double quotes.
And as for the curly braces:
«Any scalar variable, array element or object property with a string
representation can be included via this syntax. Simply write the
expression the same way as it would appear outside the string, and
then wrap it in { and }. Since { can not be escaped, this syntax will
only be recognised when the $ immediately follows the {. Use {\$ to
get a literal {$.»
Check out this answer.