01--Password verification
002- sort the number which equal to its own number's cubic
003--combination of different color balls :
Note:
1-- break only will end the current cycle
2 -- continue will end the current cycle and start the next one with conditions verification.
3-- range(0,4) equals to [0,1,2,3]
4-- While Ture:
Cycle
Such statement will be used in the Games development, to make sure the Game is always online. Same cases also apply to the operation system_message cycle . Addionaly, many communication server/Client system with the same principle.