C＃-更有效的三元运算符

Question

I was making a program in which I want to check if a string is equal to "" , and if it isn't use it, but if it is, use the default value. I know I can do string != "" ? string : "default value" string != "" ? string : "default value" , however, I feel like this is inefficient, as I keep typing out string . Of course, writing out string is no problem for me, but, if in another project, I have to reference a string with a long package name, it would be a little more annoying.

Answer 1

At the moment there is no operator that can do what you want.

But there is actually a proposal for a "Default-or-Empty Coalesce operator", here:

https://github.com/dotnet/csharplang/issues/183

The best you can do at the moment is to declare an extension method like this:

    public static string NullIfEmpty(this string str)
    {
        return string.IsNullOrEmpty(str) ? null : str;
    }

and use it like this:

var foo = yourString.NullIfEmpty() ?? "default value";

Answer 2

According to DavidG's option and helpful link, you could use this extension function.

public static string IfEmpty(this string str, string alternate)
{
    return str?.Length == 0 ? str : alternate;
}

(This will return the alternate string even if the 'str' is null)

And use as mystring.IfEmpty("something else")

Source: What is the difference between String.Empty and "" (empty string)? .

Also you don't need to reference a really long string.