Why do I get a FormatException when converting a string to a float?

Question

When I try to convert a string to float:

Console.WriteLine(float.Parse("6.59"));

it throws an exception:

Unhandled Exception: System.FormatException: Input string was not in a correct f ormat.
at System.Number.ParseSingle(String value, NumberStyles options, NumberFormat Info numfmt)

When I try it like this:

Console.WriteLine(Convert.ToSingle("6.59"));

It throws the same exception:

Unhandled Exception: System.FormatException: Input string was not in a correct f ormat.
at System.Number.ParseSingle(String value, NumberStyles options, NumberFormat Info numfmt)
at System.Convert.ToSingle(String value)

Can you explain why this happens?

Answer 1

The single argument Parse method uses the current culture to parse the string. If your current culture uses some other decimal separator, this will fail.

Try using the invariant culture:

float.Parse("6.59", CultureInfo.InvariantCulture)