Originally Published: 11 July 2003
One of the frequently asked questions in various .NET developer venues is "how can I check for a numeric value if I am using C#?" The question itself is not precise because it applies equally to other .NET languages, but those using VB.NET, particularly those with a VB or VBScript background, take the IsNumeric function for granted. What they and many new .NET developers don't know is that this function is actually contained in Microsoft's Microsoft.VisualBasic.dll assembly, which can be used by any .NET language. So the comparisons in this article are just as valid for VB.NET programmers as they are for those programming in other languages.