public class Demo{
public static void main(String args[]){
/**
*Math.sqrt()//計算平方根
*Math.cbrt()//計算立方根
*Math.pow(a, b)//計算a的b次方
*Math.max( , );//計算最大值
*Math.min( , );//計算最小值
*/

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求絕對值
*/
System.out.println(Math.abs(-10.4)); //10.4
System.out.println(Math.abs(10.1)); //10.1

/**
* ceil天花板的意思，就是返回大的值
*/
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地板的意思，就是返回小的值
*/
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 取得一個大於或者等於0.0小於不等於1.0的隨機數
*/
System.out.println(Math.random()); //小於1大於0的double類型的數
System.out.println(Math.random()*2);//大於0小於1的double類型的數
System.out.println(Math.random()*2+1);//大於1小於2的double類型的數

/**
* rint 四舍五入，返回double值
* 註意.5的時候會取偶數 異常的尷尬=。=
*/
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時返回int值，double時返回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
}
}

Math類的常用方法