Java-Math类

Math类

Math类:提供一些数学运行的方法.

常用的成员方法:

public static int abs(int a):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 double max(double a,double b):获取最大值

public static double min(double a,double b):获取最小值

public static double pow(double a,double b):a的b次幂

public static double random():取值范围:[0.0,1.0)

public static long round(double a):四舍五入

public static double sqrt(double a):一个数的正平方根

相关代码:

public class mathDemo {
	public static void main(String[] args) {
		//绝对值
		System.out.println("abs:"+Math.abs(-100));
		//向上取整
		System.out.println("ceil:"+Math.ceil(11.11));
		//向下取整
		System.out.println("floor:"+Math.floor(9.99));
		//获取最大值
		System.out.println("max:"+Math.max(10, 20));
		//获取最小值
		System.out.println("min:"+Math.min(10, 20));
		//a的b次幂
		System.out.println("pow:"+Math.pow(2, 3));
		//随机获取一个1~10的整数
		System.out.println("random:"+(int)(Math.random()*9)+1);
		//四舍五入
		System.out.println("round:"+Math.round(11.11));//返回long类型
		//正平方根
		System.out.println("sqrt:"+Math.sqrt(4));
	}
}

结果为:abs:100
ceil:12.0
floor:9.0
max:20
min:10
pow:8.0
random:3
round:11
sqrt:2.0