Java Math類常用方法大全

private void mathMethod(){
 
// Math.sqrt()//計算平方根 Math.cbrt()//計算立方根 Math.hypot(x,y)//計算 (x的平方+y的平方)的平方根
 
Log.d("TAG","Math.sqrt(16)----:"+Math.sqrt(16));//4.0
Log.d("TAG","Math.cbrt(8)----:"+Math.cbrt(8));//2.0
Log.d("TAG","Math.hypot(3,4)----:"+Math.hypot(3,4));//5.0
 
 
 
// Math.pow(a,b)//計算a的b次方 Math.exp(x)//計算e^x的值
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.pow(3,2)----:"+Math.pow(3,2));//9.0
Log.d("TAG","Math.exp(3)----:"+Math.exp(3));//20.085536923187668
 
 
 
 
//Math.max();//計算最大值 Math.min();//計算最小值
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.max(2.3,4.5)----:"+Math.max(7,15));//15
Log.d("TAG","Math.min(2.3,4.5)----:"+Math.min(2.3,4.5));//2.3
 
 
 
//Math.abs求絕對值
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.abs(-10.4)----:"+Math.abs(-10.4));//10.4
Log.d("TAG","Math.abs(10.1)----:"+Math.abs(10.1));//10.1
 
 
 
//Math.ceil天花闆的意思，就是傳回大的值
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.ceil(-10.1)----:"+Math.ceil(-10.1));//-10.0
Log.d("TAG","Math.ceil(10.7)----:"+Math.ceil(10.7));//11.0
Log.d("TAG","Math.ceil(-0.7)----:"+Math.ceil(-0.7));//-0.0
Log.d("TAG","Math.ceil(0.0)----:"+Math.ceil(0.0));//0.0
Log.d("TAG","Math.ceil(-0.0)----:"+Math.ceil(-0.0));//-0.0
Log.d("TAG","Math.ceil(-1.7)----:"+Math.ceil(-1.7));//-1.0
 
 
 
//Math.floor地闆的意思，就是傳回小的值
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.floor(-10.1)----:"+Math.floor(-10.1));//-11.0
Log.d("TAG","Math.floor(10.7)----:"+Math.floor(10.7));//10.0
Log.d("TAG","Math.floor(-0.7)----:"+Math.floor(-0.7));//-1.0
Log.d("TAG","Math.floor(0.0)----:"+Math.floor(0.0));//0.0
Log.d("TAG","Math.floor(-0.0)----:"+Math.floor(-0.0));//-0.0
 
 
 
//Math.random 取得一個大于或者等于0.0小于不等于1.0的随機數[0,1)
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.random()----:"+Math.random());//輸出[0,1)間的随機數 0.8979626325354049
Log.d("TAG","Math.random()*100----:"+Math.random()*100);//輸出[0,100)間的随機數 32.783762836248144
 
 
 
 
// Math.rint 四舍五入 傳回double值
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.rint(10.1)----:"+Math.rint(10.1));//10.0
Log.d("TAG","Math.rint(10.7)----:"+Math.rint(10.7));//11.0
Log.d("TAG","Math.rint(-10.5)----:"+Math.rint(-10.5));//-10.0
Log.d("TAG","Math.rint(-10.51)----:"+Math.rint(-10.51));//-11.0
Log.d("TAG","Math.rint(-10.2)----:"+Math.rint(-10.2));//-10.0
Log.d("TAG","Math.rint(9)----:"+Math.rint(9));//9.0
 
 
 
//Math.round 四舍五入 float時傳回int值，double時傳回long值
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.round(10.1)----:"+Math.round(10.1));//10
Log.d("TAG","Math.round(10.7)----:"+Math.round(10.7));//11
Log.d("TAG","Math.round(-10.5)----:"+Math.round(-10.5));//-10
Log.d("TAG","Math.round(-10.51)----:"+Math.round(-10.51));//-11
Log.d("TAG","Math.round(-10.2)----:"+Math.round(-10.2));//-10
Log.d("TAG","Math.round(9)----:"+Math.round(9));//9
 
 
 
//Math.nextUp(a) 傳回比a大一點點的浮點數
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.nextUp(1.2)----:"+Math.nextUp(1.2));//1.2000000000000002
 
 
//Math.nextDown(a) 傳回比a小一點點的浮點數
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.nextDown(1.2)----:"+Math.nextDown(1.2));//1.1999999999999997
 
 
 
//Math.nextAfter(a,b) 傳回(a,b)或(b,a)間與a相鄰的浮點數 b可以比a小
 
Log.d("TAG","------------------------------------------");
Log.d("TAG","Math.nextAfter(1.2, 2.7)----:"+Math.nextAfter(1.2, 2.7));//1.2000000000000002
Log.d("TAG","Math.nextAfter(1.2, -1)----:"+Math.nextAfter(1.2, -1));//1.1999999999999997
 
}