Java中判断成绩
int number =80;
if (number < 0 || number > 100) { System.out.println("输入的成绩是错误的：");
} else if (number >= 90 && number <= 100) { System.out.println("优");
} else if (number >= 80 && number <= 89) { System.out.println("良");
} else if (number >= 70 && number <= 79) { System.out.println("中");
} else if (number >= 60 && number <= 69) { System.out.println("及格");
} else if (number >= 0 && number <= 60) { System.out.println("不及格");
}