18. An electronic device comprising:an object;
another object; and
a positioning module comprising:a positioning element rotatably disposed at the object;
an arc-shaped guiding unit disposed between the positioning element and the object and configured to enable the positioning element to rotate on an arc center of the arc-shaped guiding unit;
an actuating element connected to the positioning element and configured to drive the positioning element; and
a magnetic element disposed at the another object and configured to drive the actuating element,
wherein an engaging surface of the object is connected to another engaging surface of the another object, and a position of the actuating element corresponds to the magnetic element, so that a portion of the positioning element extends into another accommodation space of the another object, and the object and the another object are selectively combined with each other via the positioning module.