Portable keyboard

A keyboard comprising:

• a plurality of key assemblies, each key assembly including a corresponding plurality of keytops;
• a body part provided adjacent to a first one of the key assemblies located on a first end of the plurality of key assemblies, the body part has a plurality of periphery surfaces of a polygonal cylinder;
• and a flexible connecting member to electrically connect the body part to each of the plurality of key assemblies, wherein a top of each of the plurality of keytops of each separate one of the key assemblies face a separate corresponding periphery surface of the body part in a first-transform state, and the top of each of the plurality of keytops is exposed to outside of the keyboard in a second transform state, wherein the portable keyboard is provided in a polygonal cylinder shape in the first transform state.