How can a 360? servo motor work like a DC motor to run as wheel for a robot, how to program it? use "++" and "--" function?
Some value near 90° will make the servo stop (or get very close to stopping). Values less than that will cause the servo to spin in one direction. Values greater than that will cause the servo to spin in the other direction. Usually, the further the value is from the stop value the faster the servo will spin.
The 360° servo has ben modified to break the feedback loop and set the feedback resistor to always say "you are currently at the mid point (about 90°)". Control signals that try to move the servo away from the midpoint will cause the servo to spin, trying to get from the midpoint to whatever position the control signal is requesting. Since the feedback never changes the servo continues to spin trying to get to the new position.
You can program it using the in built servo library that comes with the arduino IDE (software).
Heres a link to get you started: Servo - Arduino Reference
The library makes it very simple