成員:
/* 欄位 */Math.E; //2.71828182845905Math.PI; //3.14159265358979/* 靜態方法 */Math.Abs; //絕對值Math.Acos; //反餘弦Math.Asin; //反正弦Math.Atan; //反正切Math.Atan2; //反正切, 兩參數Math.BigMul; //int32 * int32 = int64Math.Ceiling; //取 >= 的最小整數Math.Cos; //餘弦Math.Cosh; //雙曲餘弦Math.DivRem; //取商和餘數Math.Exp; //求 e 的指定次冪Math.Floor; //取
練習:
//Truncate()、Floor()、Ceiling()protected void Button1_Click(object sender, EventArgs e){ double n1 = Math.Truncate(Math.PI); // 3 double n2 = Math.Floor(2.5); // 2 double n3 = Math.Floor(-2.5); //-3 double n4 = Math.Ceiling(2.5); // 3 double n5 = Math.Ceiling(-2.5); //-2 TextBox1.Text = string.Concat(n1, "\n", n2, "\n", n3, "\n", n4, "\n", n5);}//就近舍入(取偶)protected void Button2_Click(object sender, EventArgs e){ double n1 = Math.Round(0.5); // 0 double n2 = Math.Round(1.5); // 2 double n3 = Math.Round(2.5); // 2 double n4 = Math.Round(3.5); // 4 double n5 = Math.Round(-0.5); // 0 double n6 = Math.Round(-1.5); //-2 double n7 = Math.Round(-2.5); //-2 double n8 = Math.Round(-3.5); //-4 TextBox1.Text = string.Concat(n1, "\n", n2, "\n", n3, "\n", n4, "\n", n5, "\n", n6, "\n", n7, "\n", n8);}//四捨五入protected void Button3_Click(object sender, EventArgs e){ double n1 = Math.Round(0.5, MidpointRounding.AwayFromZero); // 1 double n2 = Math.Round(1.5, MidpointRounding.AwayFromZero); // 2 double n3 = Math.Round(2.5, MidpointRounding.AwayFromZero); // 3 double n4 = Math.Round(3.5, MidpointRounding.AwayFromZero); // 4 double n5 = Math.Round(-0.5, MidpointRounding.AwayFromZero); //-1 double n6 = Math.Round(-1.5, MidpointRounding.AwayFromZero); //-2 double n7 = Math.Round(-2.5, MidpointRounding.AwayFromZero); //-3 double n8 = Math.Round(-3.5, MidpointRounding.AwayFromZero); //-4 TextBox1.Text = string.Concat(n1, "\n", n2, "\n", n3, "\n", n4, "\n", n5, "\n", n6, "\n", n7, "\n", n8);}//指定小數位元(0..28)的舍入protected void Button4_Click(object sender, EventArgs e){ double n1 = Math.Round(3.126, 2); // 3.13 double n2 = Math.Round(3.124, 2); // 3.12 double n3 = Math.Round(3.125, 2); // 3.12 double n4 = Math.Round(3.135, 2); // 3.14 double n5 = Math.Round(3.125, 2, MidpointRounding.AwayFromZero); // 3.13 double n6 = Math.Round(3.135, 2, MidpointRounding.AwayFromZero); // 3.14 TextBox1.Text = string.Concat(n1, "\n", n2, "\n", n3, "\n", n4, "\n", n5, "\n", n6);}