Returning multiple results from a method [duplicate]

Answer 1

I wouldn't return the error message. Return a meaningful value or error out and let it bubble up. How you handle the error is up to you, but at a minimum I would gracefully handle it on the front end and log/notify someone on the backend.

If you insist on returning something even when your function errors out then I would return an object that has the following members:

Value - String
Success - Bool

Then you can check for success and handle the value accordingly.

Answer 2

A pretty way to do this is return an object that includes both a Success/Failure status and a detailed error message.

Something like:

class Result
{
   bool IsSuccessful { get; set; }
   string DetailedStatus { get; set; }
}

Answer 3

Try a tuple?

public Tuple<bool, string> ReturnsBoolAndString() {
    return Tuple.Create(false, "string");
}

Answer 4

2 possibilities spring to mind

1. Use the TryXXX pattern (used in some BCL methods such as DateTime.TryParse).
2. Design a class that contains the status of the operation and the result and then have your method return this class.

Let's first see the TryXXX pattern. It's basically a method that returns a boolean value and the result as out parameter.

public bool TryXXX(string someInput, out string someResult, out string errorMessage)
{
    ...
}

which will be consumed like this:

string someResult;
string errorMessage;
if (!TryXXX("some parameter", out someResult, out errorMessage))
{
    // an error occurred => use errorMessage to get more details
}
else
{
    // everything went fine => use the results here
}

In the second approach you would simply design a class that will contain all the necessary information:

public class MyResult
{
    public bool Success { get; set; }
    public string ErrorMessage { get; set; }

    public string SomeResult { get; set; }
}

and then have your method return this class:

public MyResult MyMethod(string someParameter)
{
    ...
}

which will be consumed like this:

MyResult result = MyMethod("someParameter");
if (!result.Success)
{
    // an error occurred => use result.ErrorMessage to get more details
}
else
{
    // everything went fine => use the result.SomeResult here
}

Of course the results can be any other complex object instead of (as shown in this example) a string.

Answer 5

Why don't you create a class with 3 properties. success (bool), message (string) and token (string). You can create an instance of that class, populate the values and return that.