Java学习之Math类

一、概念

用于执行数学运算的类

二、成员方法

  public static int abs(int a)//取绝对值

  public static double ceil(double a)//向上取整

  public static double floor(double a)//向下取整

  public static int max(int a,int b) //返回两个数中的最大值

  public static double pow(double a,double b)  a的b次方

  public static double random()//返回一个double类型的随机数。范围在0.0到1.0之间

  public static int round(float a)// 返回最接近参数的 int

举例：

public class MathDemo {public static void main(String[] args) {//public static int abs(int a)//取绝对值int a = -10;System.out.println(Math.abs(a));//10//public static double ceil(double a)//向上取整double b = 5.6;double c = 5.3;System.out.println(Math.ceil(b));//6.0System.out.println(Math.ceil(c));//6.0// public static double floor(double a)//向下取整System.out.println(Math.floor(b));//5.0System.out.println(Math.floor(c));//5.0//public static int max(int a,int b) //取两个数中间的最大值//public static int min(int a,int b) //取两个数中间的最小值int e = 5;int f = 10;System.out.println(Math.max(e, f));//10System.out.println(Math.min(e, f));//5//public static double pow(double a,double b)//a的b次方double b2 = 5.0;double c2 = 2.0;System.out.println(Math.pow(b2, c2));//25.0//public static double random()返回带正号的 double 值，该值大于等于 0.0 且小于 1.0。System.out.println(Math.random());//public static int round(float a) 返回最接近参数的 int//public static int round(double a) 返回最接近参数的 longfloat g = 10+0.5f;double h = 10+0.5d;System.out.println(Math.round(g));//11System.out.println(Math.round(h));//11}}