Truncating decimal points

[prakashdehury]

can some one pls suggest me why?

StreamWriter sw = new StreamWriter(@"c:\Temp\1.txt");
double dd1;
double dd2;
double dd3;
double dd4;
dd1 = 1452.123456789876123456;
dd2 = 1452.123456789123123456;
dd3 = 1452.123456789567123456;
dd4 = 1452.123456789456123456;

sw.WriteLine(dd1.ToString());
sw.WriteLine(dd2.ToString("G"));
sw.WriteLine(dd3);
sw.WriteLine(dd4);
sw.Close();


Output
----------
1452.12345678988
1452.12345678912
1452.12345678957
1452.12345678946


why it round off the values to 11 decimal places?

Thanks
Prakash

 

[Marc Gravell]

See http://msdn2.microsoft.com/en-us/library/kfsatb94(VS.80).aspx

For the [G]eneral format, up to 15 digits are returned; you can ask
for 17... double simply can't guarantee 22... have a closer look at
what is stored... you will probably find that dd1-4 have wandered
somewhat from the numbers you specified.

Marc

 

[Jon Skeet [C# MVP]]

can some one pls suggest me why?

why it round off the values to 11 decimal places?

See http://pobox.com/~skeet/csharp/floatingpoint.html

Jon