1 System.out.println(Math.round(-12.7));//输出-13 2 System.out.println(Math.round(-12.5));//输出-12 3 System.out.println(Math.round(-12.4));//输出-12 4 System.out.println(Math.round(12.5));//输出13 5 System.out.println(Math.round(12.4));//输出12 6 7 System.out.println("------------"); 8 9 System.out.println(Math.ceil(1.5));//输出2.0 10 System.out.println(Math.ceil(1.4));//输出2.0 11 System.out.println(Math.ceil(-1.5));//输出-1.0 12 System.out.println(Math.ceil(-1.6));//输出-1.0 13 System.out.println(Math.ceil(-1.4));//输出-1.0 14 15 System.out.println("------------"); 16 17 System.out.println(Math.floor(1.5));//输出1.0 18 System.out.println(Math.floor(1.4));//输出1.0 19 System.out.println(Math.floor(-1.6));//输出-2.0 20 System.out.println(Math.floor(-1.5));//输出-2.0 21 System.out.println(Math.floor(-1.4));//输出-2.0