Java Number & Math 类

/**
 * Java Number & Math 类
 */
public class learn_9 {
    public static void main(String[] args) {
        Integer a = 15;
        a = a + 2;
        System.out.println(a);
        System.out.println(Math.floor(4.1));
        System.out.println(Math.round(4.1));
        System.out.println(Math.ceil(4.1));

        double [] nums = {1.2,2.3,3.4,4.5};
        for (double num : nums) {
            test(num);
        }
    }

    private static void test(double num) {
        System.out.println("Math.floor(" + num + ")=" + Math.floor(num));
        System.out.println("Math.round(" + num + ")=" + Math.round(num));
        System.out.println("Math.ceil(" + num + ")=" + Math.ceil(num));
    }
}