JAVA中Math类用法

左手的ㄟ右手 2024-04-17 05:52 77阅读 0赞

public class Demo{
        public static void main(String args[]){  
            /** 
             *Math.sqrt()//平方根
             *Math.cbrt()//立方根
             *Math.pow(a, b)//a的b次方
             *Math.max( , );//最大值
             *Math.min( , );//最小值
             */  
            System.out.println(Math.sqrt(16));   //4.0 
            System.out.println(Math.cbrt(8));    //2.0
            System.out.println(Math.pow(3,2));     //9.0
            System.out.println(Math.max(2.3,4.5));//4.5
            System.out.println(Math.min(2.3,4.5));//2.3
            /** 
             * abs求绝对值 
             */  
            System.out.println(Math.abs(-10.4));    //10.4  
            System.out.println(Math.abs(10.1));     //10.1  
            /** 
             * ceil取天花板
             */  
            System.out.println(Math.ceil(-10.1));   //-10.0  
            System.out.println(Math.ceil(10.7));    //11.0  
            System.out.println(Math.ceil(-0.7));    //-0.0  
            System.out.println(Math.ceil(0.0));     //0.0  
            System.out.println(Math.ceil(-0.0));    //-0.0  
            System.out.println(Math.ceil(-1.7));    //-1.0
            /** 
             * floor取底板
             */  
            System.out.println(Math.floor(-10.1));  //-11.0  
            System.out.println(Math.floor(10.7));   //10.0  
            System.out.println(Math.floor(-0.7));   //-1.0  
            System.out.println(Math.floor(0.0));    //0.0  
            System.out.println(Math.floor(-0.0));   //-0.0  
            /** 
             * random 取得一个大于或者等于0.0小于不等于1.0的随机数 
             */  
            System.out.println(Math.random());  //小于1大于0的double类型的数
            System.out.println(Math.random()*2);//大于0小于1的double类型的数
            System.out.println(Math.random()*2+1);//大于1小于2的double类型的数
            /** 
             * rint 四舍五入，返回double值 
             *遇到0.5的时候会取偶数    也就是10.5取10,11.5取12
             */  
            System.out.println(Math.rint(10.1));    //10.0  
            System.out.println(Math.rint(10.7));    //11.0  
            System.out.println(Math.rint(11.5));    //12.0  
            System.out.println(Math.rint(10.5));    //10.0  
            System.out.println(Math.rint(10.51));   //11.0  
            System.out.println(Math.rint(-10.5));   //-10.0  
            System.out.println(Math.rint(-11.5));   //-12.0  
            System.out.println(Math.rint(-10.51));  //-11.0  
            System.out.println(Math.rint(-10.6));   //-11.0  
            System.out.println(Math.rint(-10.2));   //-10.0  
            /** 
             * round 四舍五入，float时返回int值，double时返回long值 
             */  
            System.out.println(Math.round(10.1));   //10  
            System.out.println(Math.round(10.7));   //11  
            System.out.println(Math.round(10.5));   //11  
            System.out.println(Math.round(10.51));  //11  
            System.out.println(Math.round(-10.5));  //-10  
            System.out.println(Math.round(-10.51)); //-11  
            System.out.println(Math.round(-10.6));  //-11  
            System.out.println(Math.round(-10.2));  //-10  
        }  
    }