Ch. 5 white book code

#include <Servo.h>
Servo myServo ;
int const Servopin = 9 ;
int const potentiometerPin = A0 ;
int potentiometerVal ;
int angle ;
void setup()
{
  myServo.attach(Servopin) ;
  Serial.begin(9600) ;
}
void loop()
{
  potentiometerVal = analogRead(potentiometerPin) ;
  Serial.print("potentiometerVal: ") ;
  Serial.print(potentiometerVal);
  angle = map(potentiometerVal, 0, 1023, 0, 180) ;
  Serial.print(" angle: ");
  Serial.println(angle);
  myServo.write(angle) ;
  delay(500) ;
}