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");}