Question

I find myself often needing to use int.TryParse() to test if a value is an integer. However, when using TryParse, I have to pass a reference variable to the function. So I find myself always needing to create a temp int to be passed in. Usually it looks something like:

int my_temp_integer;

int.TryParse(potential_integer, my_temp_integer);

I find this to be quite cumbersome considering that all I want is a simple true/false response, and I don’t care about the actual parsed result. Is there a better way to approach this? Why isn’t there an overloaded function where I can just pass the value I want to test and get a true/false response?

Thanks.

Answer 1

you could write an extension method:

public static bool IsInt(this string pString)
{
   int value;
   return int.TryParse(pString, out value);
}

then your example becomes:

potential_integer.IsInt();

EDIT:
Lately I have been using a generic form of this.

public delegate bool TryParser<T>(string pString, out T pResult);

public static bool Is<T>(this string pString, TryParser<T> pTryParser)
{
   T val;
   return pTryParser(pString, out val);
}

Can then use it as follows; it’s not perfect, but it’s more concise than anything I’ve found:

"1234".Is<int>(int.TryParse);       // true
"asdf123".Is<int>(int.TryParse);    // false
"1.2345".Is<float>(float.TryParse); // true
"1000".Is<byte>(byte.TryParse);     // false

Theoretically, this would also work with custom TryParse methods, as long as you followed the same pattern as the official ones.

Update: If you maintain a static dictionary of TryParse methods by type, you can avoid having to ever directly pass the method. The dictionary can even be populated as needed with reflection.