Sanwa joystick on Arduino example code

joystick

//A0 = green, A1 = yellow, A2 = orange, A3 = red
#define downPin 14
#define upPin 15
#define rightPin 16
#define leftPin 17
 
 
void setup() {
  Serial.begin(9600);
 
  //Joystick setup
  pinMode(downPin, INPUT);
  digitalWrite(downPin, HIGH);
  pinMode(upPin, INPUT);
  digitalWrite(upPin, HIGH);
  pinMode(rightPin, INPUT);
  digitalWrite(rightPin, HIGH);
  pinMode(leftPin, INPUT);
  digitalWrite(leftPin, HIGH);
 
 
  int X = 0;
  int Y = 0;
}
 
void loop() {
  joystick( &X, &Y );
  result(X,Y);
}
 
void joystick(int* X, int* Y){
  
  //HIGH = non-trigger
  if( !digitalRead( leftPin ) ){
    *X = 0;
  }else if( !digitalRead( rightPin ) ){
    *X = 1;
  }else{
    *X = -1;
  }
  
  if( !digitalRead( upPin ) ){
    *Y = 1;
  }else if( !digitalRead( downPin ) ){
    *Y = 0;
  }else{
    *Y = -1;
  }
  
}
 
void result( X, Y ) {
  Serial.print(X);
  Serial.print('\t');
  Serial.print(Y);
  Serial.println('');
}