6、1 while 语句
6、2 循环的执行阶段
Iteration, Loop test, loop exit, Termination condition
6、3 使用while语句的循环
Count-Controlled Loops and Event-Controlled Loops
Looping Subtasks:
Counting, Summing, Keeping track of a previous value
6、4 如何设计循环
What is the condition that ends the loop?
How should the condition be initialized?
How should the condition be updated?
What is the process being repeated?
How should the process be initialized?
How should the process be updated?
What is the state of the program on exiting the looping?
6、5 内装的逻辑
