@Instance("ModID")

public static ClassName instance;

How does this work? I understand it makes an Instance from which MinecraftForge can work from, but how does it achieve this?

Also, what's the difference between the aformentioned code and this:

@Instance

public static ClassName instance = new ClassName();

 

Do they both achieve the same thing?

 

The Instance annotation sets the field to the specific instance of your mod that Forge is using internally via reflection. You shouldn't instantiate your mod class yourself, the one you've instantiated won't be the one Forge uses.

@Instance("ModID")

public static ClassName instance;

How does this instantiate anything though?

@Instance("ModID") so here I pass along the ModID as a string to this annotation...

public static ClassName instance; how does this line set the field to the instance of my mod? is the word instance here connected to the annotation @Instance?

 

@Instance

public static ClassName instance = new ClassName();

Why does this one still work?

@Instance why is there no ModID being passed along here?

public static ClassName instance = new ClassName(); doesn't this make more sense as it is creating a New instance? Is it this one you said won't be the one forge uses?

FML will construct any @Mod it finds.

It will also apply any @Instance it finds.

If it finds a @Instance with no modid inside a class with a @Mod it will assume that it wants its own instance.

 

Calling new ClassName() yourself creates a extra instance of your class that is never used because that field would be instantly replaced by FML to the instance that FML created.

@Instance("ModID")

public static ClassName instance;

How does this instantiate anything though?

@Instance("ModID") so here I pass along the ModID as a string to this annotation...

public static ClassName instance; how does this line set the field to the instance of my mod? is the word instance here connected to the annotation @Instance?

 

FML scans for all Instance annotations and uses reflection to populate the field with the instance of your mod being used internally. No, the field name is not connected.

 

@Instance

public static ClassName instance = new ClassName();

Why does this one still work?

@Instance why is there no ModID being passed along here?

public static ClassName instance = new ClassName(); doesn't this make more sense as it is creating a New instance? Is it this one you said won't be the one forge uses?

 

You still need to pass in the mod id to the annotation.

 

Yes, the only correct instance of your mod is the one created by Forge, not one you yourself instantiate.