public function correctToJSON(){
        $returnValue = null;

        try{
            $correctResponses = $this->getCorrectResponses();
            if(count($correctResponses)){
                $returnValue = taoQTI_models_classes_Matching_VariableFactory::createJSONVariableFromQTIData(
                    $this->getIdentifier()
                    , $this->getAttributeValue('cardinality')
                    , $this->getAttributeValue('baseType')
                    , $this->correctResponses
                );
            }
        }catch(Exception $e){

        }

        return $returnValue;
    }
public function correctToJSON(){
        $returnValue = null;

        try{
            $correctResponses = $this->getCorrectResponses();
            if(count($correctResponses)){
                $returnValue = taoQTI_models_classes_Matching_VariableFactory::createJSONVariableFromQTIData(
                    $this->getIdentifier()
                    , $this->getAttributeValue('cardinality')
                    , $this->getAttributeValue('baseType')
                    , $this->correctResponses
                );
            }
        }catch(Exception $e){

        }

        return $returnValue;
    }
public function correctToJSON ( ) { $ returnValue = null ; try { $ correctResponses = $ this -> getCorrectResponses ( ) ; if ( count ( $ correctResponses ) ) { $ returnValue = taoQTI_models_classes_Matching_VariableFactory :: createJSONVariableFromQTIData ( $ this -> getIdentifier ( ) , $ this -> getAttributeValue ( 'cardinality' ) , $ this -> getAttributeValue ( 'baseType' ) , $ this -> correctResponses ) ; } } catch ( Exception $ e ) { } return $ returnValue ; }
get the correct response in JSON format. If no correct response defined
null.

@deprecated now use the new qtism lib for response evaluation
@access public
@author Joel Bout, <joel.bout@tudor.lu>
get the correct response in JSON format . If no correct response defined null .