C#:Converting between number types

C#:Simple Types

Base Types

Convert to String

Convert to Number

Converting between number types

Loss of precision

Casting

When converting from a floating point number to an integer there is likely to be a loss of precision - for example 3.1 will become 3.

When converting from an integer to a floating point there is no such danger.

integer to floating point

Not much can go wrong. The conversion is automatic.

However notice:

• the calculation i/10 is performed as an integer

calculation and gives 123.0

• the calculation i/10.0 is performed as a floating point calculation

and gives 123.4

.

using System; public class Demo{ public static void Main(String[] argv) { int i = 1234; double d = i; Console.WriteLine(d); double e = i/10; //Yields 123.0 Console.WriteLine(e); double f = i/10.0; //Yields 123.4 Console.WriteLine(f); } }

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test text

 

 

 

 

Rounding to an integer

We can use Math.Round to round up or down then cast to a long

We can simply cast explicitly and have the fractional part of the number discarded.

.

using System; public class Demo{ public static void Main(String[] argv) { double d = 3.8; long i = (long)Math.Round(d); Console.WriteLine(i); int j = (int) d; Console.WriteLine(j); } }

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test text