Call one of two methods dynamically

Question

Is there a way to convert this if/else statement so that it can be called in a more dynamic way without using reflection?

if (left.IsColliding()) directions.Remove(Direction.Left);
else directions.Add(Direction.Left);

In JavaScript I can do the following and I was wondering if there was something similar in C#.

directions[left.IsColliding() ? "Remove" : "Add"](Direction.Left);

There are many available source code obfuscators which will achieve the same effect more thoroughly and effectively. — 15ee8f99-57ff-4f92-890c-b56153, Sep 27 '19 at 16:36
This might be a better fit for [Code Review](https://codereview.stackexchange.com). — 15ee8f99-57ff-4f92-890c-b56153, Sep 27 '19 at 16:41
If you have a large logic sequence, perhaps a simple application of the Chain of Responsibility pattern concept would help. — Tom Blodget, Sep 27 '19 at 16:54

score 0 · Answer 1 · 2019-09-27T18:13:42.620

0

Not possible in C#.

What is the problem with your code that It is fine and simple.

The javascript version is ugly and problematic because using strings hard coded to call methods is a potential source of bugs and it is unmaintainable.

But you can write this:

switch ( left.IsColliding() )
{
  case true:
    directions.Remove(Direction.Left);
    break;
  case false:
    directions.Add(Direction.Left);
    break;
}

edited Sep 27 '19 at 18:13

answered Sep 27 '19 at 16:43

1

I think what OP is looking for is not just any old bad code, but bad code that's specifically fragile, cryptic, and terse. I don't see any of those last three requirements being met here. – 15ee8f99-57ff-4f92-890c-b56153 Sep 27 '19 at 17:09
1

The switch was a joke... – Sep 27 '19 at 17:16
1

So was my comment. – 15ee8f99-57ff-4f92-890c-b56153 Sep 27 '19 at 17:17

score 0 · Answer 2 · answered Sep 27 '19 at 16:47

0

Have a look at Func<T, TResult>

It let's you essential define a function and then call it at a later time.

So you could have functions with your strings Remove and Add as keys to a Dictionary<string, Func<T, TResult>.

You can use a Ternary with the same syntax you mentioned for JavaScript. So you would just use that instead of your if statement.

https://learn.microsoft.com/en-us/dotnet/api/system.func-2?view=netframework-4.8

I think I'm answering your question, but based on some comments in your question (which I am unable to comment on as of yet), I'm slightly concerned I did not.

answered Sep 27 '19 at 16:47

Paul Ferguson

39
4

Given that OP's question is essentially a request for a way to obfuscate the code, I think this is a reasonable answer to the question OP asked. – 15ee8f99-57ff-4f92-890c-b56153 Sep 27 '19 at 16:49
Cool. Thanks for reassuring my insecure self. :D – Paul Ferguson Sep 27 '19 at 16:53

score -1 · Answer 3 · answered Sep 27 '19 at 16:47

-1

A ternary operator must return something. You can do something like this to return an Action delegate which has the effect you're looking for:

int a = 5;
int b = 10;
(a == b ? (Action)doThis : doThat)();

Where doThis and doThat are methods.

answered Sep 27 '19 at 16:47

RyanHx

411
3
10

This is potentially a nice solution: It compiles, and it has the desired effect on readability and maintainability. However, it needs to be adapted to call instance methods on the `directions` collection. – 15ee8f99-57ff-4f92-890c-b56153 Sep 27 '19 at 16:52
2

Instead of copying someone else's answer to a similar question, please vote to close this question as a duplicate instead (this answer is a copy of: https://stackoverflow.com/questions/5490095/method-call-using-ternary-operator) – Rufus L Sep 27 '19 at 17:29

Call one of two methods dynamically

3 Answers3