Java Math class method outlined and its members

Math class overview

 

Math class contains methods for performing basic mathematical operations, like ever exponential, logarithmic, trigonometric functions and square root.

 

 

 

 

Member method

• public static int abs(int a)
• public static double ceil(double a)
• public static double floor(double a)
• static public int max ( int A, int B ) min Self
• public static double pow(double a,double b)
• public static double random()
• public static int round (A a float ) parameter double self-study
• public static double sqrt(double a)

package cn.wen;

public class MathDemo {
	public static void main(String[] args) {
		// public static final double PI
		System.out.println("PI:" + Math.PI);
		// public static final double E
		System.out.println("E:" + Math.E);
		System.out.println("--------------");

		// public static int abs(int a)：绝对值
		System.out.println("abs:" + Math.abs(10));
		System.out.println("abs:" + Math.abs(-10));
		System.out.println("--------------");

		// public static double ceil(double a):向上取整
		System.out.println("ceil:" + Math.ceil(12.34));
		System.out.println("ceil:" + Math.ceil(12.56));
		System.out.println("--------------");

		// public static double floor(double a):向下取整
		System.out.println("floor:" + Math.floor(12.34));
		System.out.println("floor:" + Math.floor(12.56));
		System.out.println("--------------");


		// public static int max(int a,int b):最大值
		System.out.println("max:" + Math.max(12, 23));
		// 需求：我要获取三个数据中的最大值
		// 方法的嵌套调用
		System.out.println("max:" + Math.max(Math.max(12, 23), 18));
		// 需求：我要获取四个数据中的最大值
		System.out.println("max:"
				+ Math.max(Math.max(12, 78), Math.max(34, 56)));
		System.out.println("--------------");

		// public static double pow(double a,double b):a的b次幂
		System.out.println("pow:" + Math.pow(2, 3));
		System.out.println("--------------");

		// public static double random():随机数 [0.0,1.0)
		System.out.println("random:" + Math.random());
		// 获取一个1-100之间的随机数
		System.out.println("random:" + ((int) (Math.random() * 100) + 1));
		System.out.println("--------------");

		// public static int round(float a) 四舍五入(参数为double的自学)
		System.out.println("round:" + Math.round(12.34f));
		System.out.println("round:" + Math.round(12.56f));
		System.out.println("--------------");
		
		//public static double sqrt(double a):正平方根
		System.out.println("sqrt:"+Math.sqrt(4));
	}
}