Ytdyklly

When I'm checking some conditions to return one of a small handful of values, I often end up nesting several ternary conditional operators (?:) rather than using a series of if..elseif statements.

As a simple example of this, presume I have:

    public enum StringValueType 

    {

        Null,

        Empty,

        Short,

        Long

    }



    public string Value { get; set; }

I'm trying to return the appropriate StringValueType value in a property:

    public StringValueType ValueType => 

        Value == null ? StringValueType.Null

        : Value == string.Empty ? StringValueType.Empty

        : Value.Length < 8 ? StringValueType.Short

        : StringValueType.Long;

Is this readable? Are there downsides? I'm not sure I've ever come across this in other people's code before.

For comparison, some alternate ways this might be written:

If-else

    public StringValueType ValueType

    {

        get

        {

            if (Value == null)

                return StringValueType.Null;

            else if (Value == string.Empty)

                return StringValueType.Empty;

            else if (Value.Length < 8)

                return StringValueType.Short;

            else

                return StringValueType.Long;

        }

    }

Switch+Conditional

    public StringValueType ValueType

    {

        get

        {

            switch (MatchedDefinitionName)

            {

                case null:

                    return StringValueType.Null;

                case "":

                    return StringValueType.Empty;

                default:

                    return Value.Length < 8 ? StringValueType.Short : StringValueType.Long;

            }

        }

    }

The ternary operator is almost never the readable way to go, which is one of the big reasons you see it so rarely. If you do want to use it, you might want to consider some vertical alignment to make it more legible.

    public StringValueType ValueType => 

        Value == null           ? StringValueType.Null

        : Value == string.Empty ? StringValueType.Empty

        : Value.Length < 8      ? StringValueType.Short

        :                         StringValueType.Long;

That said, vertical alignment is a bit controversial; I find it immensely helpful, but I know a lot of programmers who hate it. I would explain their reasoning, except that none of them have ever explained a coherent reason to me apart from them not being used to it.

While switch statements are frequently the most legible option, since it can't handle a significant portion of the logic, I would probably lean towards your if-else version.

That said, if there were 10-20 cases, and the switch could handle almost all of them, with just one or two having additional logic, I'd probably go with the switch in those cases.