System.Convert.ToDouble

[Jason]

In VB.NET, when I use System.Convert.ToDouble(string Val) to convert a string
variable to double variable, I got something interesting:

Dim stringVal As String = "101.01"
Dim doubleVal As Double
doubleVal = System.Convert.ToDouble(stringVal)
Msgbox (doubleVal) will return 101.01

but......
Dim stringVal As String = "101.00"
Dim doubleVal As Double
doubleVal = System.Convert.ToDouble(stringVal)
Msgbox (doubleVal) will return 101

where is the ".00" ?
Should I get 101.00 instead of 101?

Did I missed something here?
TIA

 

[Marina]

Why do you think you should have the 00? 101.00=101. And 101 happens to be
what happens when the tostring method is called in this case (which is
called implicitly, since you are not doing it explicitly).

If you want the decimal places to always show up, you should use custom
format strings to ensure that the formatting to your liking - otherwise you
will get default behavior. But I am not sure why you feel there is something
wrong with the default behavior.

 

[Herfried K. Wagner [MVP]]

In VB.NET, when I use System.Convert.ToDouble(string Val) to convert a string
variable to double variable, I got something interesting:

Dim stringVal As String = "101.01"
Dim doubleVal As Double
doubleVal = System.Convert.ToDouble(stringVal)
Msgbox (doubleVal) will return 101.01

but......
Dim stringVal As String = "101.00"
Dim doubleVal As Double
doubleVal = System.Convert.ToDouble(stringVal)
Msgbox (doubleVal) will return 101

where is the ".00" ?
Should I get 101.00 instead of 101?

The variable is stored in IEEE floating point format after parsing the
string. 'MsgBox' will call 'ToString' on the variable implicitly and
this will convert the variable to a string. You can specify the format
used to format the variable's value as a string in an overloaded version
of the 'ToString' method.

I suggest to turn on 'Option Strict' by placing 'Option Strict On' on
top of your source file.