java Math类方法使用

 1 package math;
 2 
 3 public class MathMethod {
 4     public static void main(String[] args) { System.out.println(Math.abs(10));//10
 5     System.out.println( Math.abs(-10));//10
 6     //pow
 7     System.out.println((int) Math.pow(2,4));//16
 8     System.out.println(Math.pow(2,-4));
 9 
10     System.out.println(Math.ceil(1.001));
11     System.out.println(Math.floor(-1.001));
12 
13     System.out.println(Math.round(1.54));
14 
15     System.out.println(Math.sqrt(9.0));
16 
17     System.out.println(Math.random());
18     int a=2;
19     int b=7;
20     int num=a+(int)(Math.random()*(b-a+1));
21     System.out.println("num="+ num);
22 
23     System.out.println(Math.max(1.0,7.8));
24     System.out.println(Math.min(12l,78l));
25 
26     }
27 }