Why can we put the result of a GetComponent<Camera> in a Behaviour array but can't do Get-CodePudding

I wanted to know why this work :

Behaviour _BehaviourArray = new Behaviour[1];
BehaviourArray[0] = GetComponent<Camera>();

But not this :

Behaviour _BehaviourArray = new Behaviour[1];
TryGetComponent<Camera>(out BehaviourArray[0]);

Which is supposed (in my mind) to give the same result if both Camera components exists.

If someone can answer me it would be highly appreciated.

Thanks.

CodePudding user response：

The indexer operator in C# is a property (or at least acts like one) and thus can't be passed into a method as an out parameter, just like any other property.

A property (or an indexer) is syntactic sugar for a getter and a setter method internally and passing it into another method as a parameter is like writing the following:

TryGetComponent(out BehaviourArray.SetValue(0, ...));

What you can do is write

Behaviour _BehaviourArray = new Behaviour[1];
TryGetComponent<Camera>(out Camera camera);
_BehaviourArray[0] = camera;

You may even wrap this in a method:

void GetComponentToArrayIndex<TComponent, TSpecificComponent>(TComponent[] array, int index) where TComponent : Component where TSpecificComponent : TComponent
{
    TryGetComponent<TSpecificComponent>(out TSpecificComponent component);
    array[index] = component;
}

and use it like this:

Behaviour _BehaviourArray = new Behaviour[1];
GetComponentToArrayIndex<Camera>(_BehaviourArray, 0);

Those are just suggestions and untested code, but that's what I would try in your case.

More info:
Indexers
out parameter modifier