Agfdhyk

is it possible to differ the variable I'm assigning to depending on a condition? The issue I came across is wanting to do this:

(bEquipAsSecondary ? currentWeaponOffhand : currentWeaponMainhand) = weaponToSwitchTo;

Instead of

if (bEquipAsSecondary)

{

    currentWeaponOffhand = weaponToSwitchTo;

}

else

{

    currentWeaponMainhand = weaponToSwitchTo;

}

Which results in the following error

Error CS0131 The left-hand side of an assignment must be a variable, property or indexer

So I was wondering if there was a way to do this to cut down on space used and - in my opinion - make it look a bit neater?

Not sure if this is really efficient, but if you really want to stick to ternary operator, here is my 2 cents...

(bEquipAsSecondary ? ref currentWeaponOffhand : ref currentWeaponMainhand) = weaponToSwitchTo;

Not sure if a ternary operator is a better choice than a regular if-else statement here. But you can use Action, something like this:

(bEquipAsSecondary ? new Action(() => currentWeaponOffhand = weaponToSwitchTo)

                   : () => currentWeaponMainhand = weaponToSwitchTo)();

The best / closest to what you're after that I could think of is this:

_ = condition ? (a = c) : (b = c);

In context:

bool condition = true;

int a = 1;

int b = 2;

int c = 3;



_ = condition ? (a = c) : (b = c);

Console.WriteLine($"a = {a}; b = {b}; c = {c}");

Outputs

a = 3; b = 2; c = 3

Explanation

• _ = is required as the ternary operator is only available if we're assigning to something. Here we use _ as the "discard" variable; i.e. we don't care about the returned value; only that the operation itself occurs.



• 
  

  use of brackets (e.g. (a = c) is required around the assignment since we need to return a result. Performing a = c assigns the value of c to a, but doesn't return anything to the caller. (a = c) on the other hand assigns c to a and then outputs the new value of a, making it available in the context of the rest of the method. i.e. Aisde from the assignments this statement effectively reads _ = condition ? c : c;.

  
  
  
  
  
  • All else is as you'd expect from the standard ternary operator. However, any questions, please say.
  
  
  
  

Thoughts

It's not ideal as you have to specify each assignment separately; but does give you a form of shorthand...

I suspect this would generally be frowned upon in a code review though, since it's less readable than the standard if/else approach...

NB: In some other languages, a trick that could be used would be to have the condition act as an index for an array (e.g. false=0, true=1) and then exploit this in assigning the value... However, whilst you can force this in C#, it's not pretty:

void Main()

{

    bool condition = true;  

    var a = new ReferenceType<int>(1);

    var b = new ReferenceType<int>(2);

    var c = new ReferenceType<int>(3);



    (new {b, a})[ConvertBoolToInt(condition)].Value = c.Value;

    Console.WriteLine($"a = {a}; b = {b}; c = {c}");    

}

//in C# bools aren't natively convertable to int as they are in many langauges, so we'd need to provide a conversion method

public int ConvertBoolToInt(bool value)

{

    return value ? 1 : 0;

}

//to allow us to change the value rather than only the refenence, we'd need to wrap our data in something and update the value assigned to its property

public class ReferenceType<T>

{

    public T Value {get;set;}

    public ReferenceType(T intValue)

    {

        Value = intValue;

    }

    public override string ToString()

    {

        return Value.ToString();

    }

}

That said, the above is talking about creating a more generic approach... If your use case is limited to weapon assignment / similar use cases, you could use a similar trick, such as this:

public enum WeaponHandEnum

{

    Primary //int = 0

    ,

    Secondary //int = 1

}

public class Player

{

    public Weapon Weapons {get;set;}

    public Player(Weapon primary = null, Weapon secondary = null)

    {

        Weapons = new Weapon[2] {primary, secondary}; 

    }

    public void Equip(WeaponHandEnum whichHand, Weapon newWeapon)

    {

        Weapons[(int)whichHand] = newWeapon;

    }

}

public class Weapon{ /* ... */ }

If you find you're having to do a lot of statements like this throughout your code and want a way to keep your line count down, you're best of with something like this:

void Main()

{

    bool condition = true;  

    var a = 1;

    var b = 2;

    var c = 3;

    SomeKindaHelper.TernaryAssign<int>(condition, ref a, ref b, c);

    Console.WriteLine($"a = {a}; b = {b}; c = {c}");    

}

public static class SomeKindaHelper

{

    public static void TernaryAssign<T>(bool condition, ref T assignToMeIfConditionIsTrue, ref T assignToMeIfConditionIsFalse, T newValue)

    {

        if (condition)

        {

            assignToMeIfConditionIsTrue = newValue;

        }

        else 

        {

            assignToMeIfConditionIsFalse = newValue;

        }

    }

}

i.e. Whilst this is several lines of code to define the helper method, you can reuse it all over the place as a one liner, and it's much more readable, if not so clever.

You can use the ternary operator to choose an action that will update the right slot.

//Define action to equip appropriate slot

var equipAction = bEquipAsSecondary

    ? new Action<Weapon>( w => currentWeaponOffhand = w )

    : new Action<Weapon>( w => currentWeaponMainhand = w );



//Now equip the weapon

equipAction(weaponToSwitchTo);