break语句通常用在循环语句和开关语句中。当break用于开关语句switch中时,可使程序跳出switch而执行switch以后的语句；如果没有break语句,则将成为一个死循环而无法退出(The break statement is usually used in the loop statement and the switch statement.When break is used in switch statement switch, the program can jump out of switch and execute the statement after switch;If there is no break statement, it will be a dead loop and unable to exi)