我可以在 C# 中使用三元运算符运行多个语句吗？

Question

I have an object named MyObject . This has a property Name.

Can I use the ternary operator like the following

string validSite = 'yahoo';
string invalidSite ='abc';
MyObject obj = new MyObject()

I want to perform a few statements in the true condition

valid ? ({ validSite; obj.Name = 'Test';})  : invalidSite

Is there a way to do this or do I need to use if-else?

Answer 1

Note below are possible solutions to the situation mentioned above but they are not recommended. As comment from @Hans Kesting on question I totally agree with using plain if...else... statement instead of one liner if your scenario is as simple as you mentioned in question.

Still this answer will help to know what could be the possible ways to achieve it and one can use it where this code fits best.

---

You can do something like below with Func define your statement inside new Func(...) and immediately invoke it with () .

var site = valid ? new Func<string>(() => { validSite; obj.Name = 'Test'; return obj.Name; })() : invalidSite;

Alternatively you can use Lazy<T> like below. Use Lazy instead of func and evaluate expression with .Value at the end.

var site = valid ? new Lazy<string>(() => { validSite; obj.Name = 'Test'; return obj.Name; }).Value : invalidSite;

---

I recommend you to use Local function which can provide re-usability of code if you need same code to repeat multiple times or else you can simply use if...else... if it fits to your requirement.

If you are using C#7 or newer version then you can use local functions . Inside this local function you can also use all local variables from parent function.

public void function Test()
{       
    var site = valid ? GetSite() : invalidSite; 
    
    string GetSite()
    {
        validSite; 
        obj.Name = 'Test'; 
        return obj.Name;
    }
}