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C# Convert Miles to Kilometers

This C# example program does a numeric conversion from miles to kilometers.
Convert miles, kilometers. A figure in miles can be converted to kilometers. The United States has standardized on miles. Most other countries use the superior metric system. It is important to maintain compatibility with many cultures.
Required input and output for distance conversion Input: 200 m 321.9 km 500 km 310.7 m Output: 321.9 km 200 m 310.7 m 500 km
Example. Here we look at some useful conversion methods for this problem. The solution consists of one static class and two methods in it. These methods are effective in converting from miles to kilometers and back again.Static

Double: Double stores numbers that are larger and have decimal places. It consumes more memory and is slower to process.

Double

Constants: Each method here uses a constant for the conversion. For regular stuff, these are fine.

Float64: The compiler will treat these constants internally as float64 values. These are in a static class, which doesn't store state.

Tip: Static classes are just a syntactic feature of the C# language, but they help clarify the code.

C# program that converts miles and kilometers using System; class Program { static void Main() { // // Convert miles to kilometers. // double miles1 = 200; double kilometers1 = ConvertDistance.ConvertMilesToKilometers(200); Console.WriteLine("{0} = {1}", miles1, kilometers1); // // Convert kilometers to miles. // double kilometers2 = 321.9; double miles2 = ConvertDistance.ConvertKilometersToMiles(321.9); Console.WriteLine("{0} = {1}", kilometers2, miles2); // // Convert kilometers to miles (again). // double kilometers3 = 500; double miles3 = ConvertDistance.ConvertKilometersToMiles(500); Console.WriteLine("{0} = {1}", kilometers3, miles3); // // Convert miles to kilometers (again). // double miles4 = 310.7; double kilometers4 = ConvertDistance.ConvertMilesToKilometers(310.7); Console.WriteLine("{0} = {1}", miles4, kilometers4); } } public static class ConvertDistance { public static double ConvertMilesToKilometers(double miles) { // // Multiply by this constant and return the result. // return miles * 1.609344; } public static double ConvertKilometersToMiles(double kilometers) { // // Multiply by this constant. // return kilometers * 0.621371192; } } Output 200 = 321.8688 321.9 = 200.0193867048 500 = 310.685596 310.7 = 500.0231808
Discussion. As I noted, the double type here is actually termed float64, meaning a 64-bit number. This snippet shows the ConvertKilometersToMiles method. You can see it uses the mul opcode to multiply.

Info: The ldrc.r8 opcode pushes the supplied value (the 0.621371192) onto the stack as a float.

Method implementation: IL .method public hidebysig static float64 ConvertKilometersToMiles(float64 k) cil managed { .maxstack 8 L_0000: ldarg.0 L_0001: ldc.r8 0.621371192 L_000a: mul L_000b: ret }
Summary. Figures in miles can be converted to km. It is interesting the extent of the loss of precision. In chemistry, there is a concept of significant digits, and that concept certainly applies here as well.

Review: We saw how the methods are converted into MSIL. We also used a static class to logically store static methods.

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