循环for、while、do...while

for格式：
https://img2024.cnblogs.com/blog/3659684/202507/3659684-20250728144146476-961151413.png

https://img2024.cnblogs.com/blog/3659684/202507/3659684-20250728144219254-1933320248.png

while循环格式：
https://img2024.cnblogs.com/blog/3659684/202507/3659684-20250728144243083-664667407.png

while和for的对比：
https://img2024.cnblogs.com/blog/3659684/202507/3659684-20250728144305433-1661481218.png

https://img2024.cnblogs.com/blog/3659684/202507/3659684-20250728144308095-341538477.png

知道次数用for，不知道次数用while

do...while语句格式：
https://img2024.cnblogs.com/blog/3659684/202507/3659684-20250728212616982-1175762335.png

无线循环格式
https://img2024.cnblogs.com/blog/3659684/202507/3659684-20250729130203195-362365422.png

无限循环下面不能写其它代码；因为循环永远停不下来，那么下面的代码永远执行不到。

跳转控制语句
continue：结束、跳过本次循环，继续下一次循环
break：结束整个循环