.NET Framework Class Library
Math.Ceiling Method (Double)
Returns the smallest integer greater than or equal to the specified double-precision floating-point number.
C#
<span style="color: blue;">public</span> <span style="color: blue;">static</span> double Ceiling (
double a
)
<h4 class="subHeading" style="font-size: 1.2em; font-weight: bold; padding: 0px; margin: 0px;">Parameters</h4><dl paramname="a"><dt><span class="parameter"><em>a</em></span> </dt><dd><p>A double-precision floating-point number. </p></dd></dl><p> </p><p> </p><h4 class="subHeading" style="font-size: 1.2em; font-weight: bold; padding: 0px; margin: 0px;">Return Value</h4>The smallest integer greater than or equal to <span class="parameter"><em>a</em></span>. If <span class="parameter"><em>a</em></span> is equal to <a target=_blank id="ctl00_rs1_mainContentContainer_ctl18" style="color: rgb(51, 102, 153); text-decoration: none;" href="http://msdn2.microsoft.com/en-us/library/system.double.nan(VS.80).aspx">NaN</a>, <a target=_blank id="ctl00_rs1_mainContentContainer_ctl19" style="color: rgb(51, 102, 153); text-decoration: none;" href="http://msdn2.microsoft.com/en-us/library/system.double.negativeinfinity(VS.80).aspx">NegativeInfinity</a>, or <a target=_blank id="ctl00_rs1_mainContentContainer_ctl20" style="color: rgb(51, 102, 153); text-decoration: none;" href="http://msdn2.microsoft.com/en-us/library/system.double.positiveinfinity(VS.80).aspx">PositiveInfinity</a>, that value is returned. // This example demonstrates Math.Ceiling() // Math.Floor()
using System;
class Sample
{
public static void Main()
{
double value;
decimal idx;
string nl = Environment.NewLine;// Return the smallest whole number greater than or equal to the specified number.
// Note that the floating point parameter used in the Math members should not also // be used as the loop index. The reason is the loop will not terminate as expected // because a floating point number only approximates a decimal number.
// For the sake of generalizing this example, the decimal index is converted to a // floating point number with the Convert class instead of a programming language- // specific type conversion.
Console.WriteLine("{0}Ceiling:", nl);
for (idx = 0.0m; idx <= 1.1m; idx += 0.1m)
{
value = Convert.ToDouble(idx);
Console.WriteLine("Ceiling({0:f}) = {1}", value, Math.Ceiling(value));
}// Return the largest whole number less than or equal to the specified number.
Console.WriteLine("{0}Floor:", nl);
for (idx = 2.1m; idx >= 1.0m; idx -= 0.1m)
{
value = Convert.ToDouble(idx);
Console.WriteLine("Floor({0:f}) = {1}", value, Math.Floor(value));
}
}
}
/*
This example produces the following results:Ceiling: Ceiling(0.00) = 0 Ceiling(0.10) = 1 Ceiling(0.20) = 1 Ceiling(0.30) = 1 Ceiling(0.40) = 1 Ceiling(0.50) = 1 Ceiling(0.60) = 1 Ceiling(0.70) = 1 Ceiling(0.80) = 1 Ceiling(0.90) = 1 Ceiling(1.00) = 1 Ceiling(1.10) = 2
Floor: Floor(2.10) = 2 Floor(2.00) = 2 Floor(1.90) = 1 Floor(1.80) = 1 Floor(1.70) = 1 Floor(1.60) = 1 Floor(1.50) = 1 Floor(1.40) = 1 Floor(1.30) = 1 Floor(1.20) = 1 Floor(1.10) = 1 Floor(1.00) = 1 */
