servo basic coding with for loop

#include(servo.h) 

Servo myServo;

void setup() {
  myServo.attach(9);
}

void loop() {

  // 0° to 180°
  for (int angle = 0; angle <= 180; angle++) {
    myServo.write(angle);
    delay(15);
  }

  // 180° to 0°
  for (int angle = 180; angle >= 0; angle--) {
    myServo.write(angle);
    delay(15);
  }

}