servo motor arduino

#include <Servo.h>

Servo myservo;  // create servo object to control a servo

void setup() {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}

void loop() {
  myservo.write(0);       // sets the servo position according to the value
  delay(1000);             // waits for the servo to reach the position
  myservo.write(90);      // sets the servo position according to the value
  delay(1000);             // waits for the servo to reach the position
  myservo.write(180);     // sets the servo position according to the value
  delay(1000);             // waits for the servo to reach the position
}