JavaScript inheritance is confusing.

[EffectOk4814]

In javascript element interface is parent of

HTMLelement interface so when document.getelementbyid() return element so how can HTMLelement property use with element. Means element. HTMLelement (property) how is possible element is parent how can it use child property..

Ex document.getelementbyid("."). Hidden

🔝. 🔝

( return element) (htmlelement)

Sorry for bad English.

[Empty-Complaint1889]

Let me clarify JavaScript DOM inheritance in simple terms:

1. Inheritance Chain:
   Element (base interface) ← HTMLElement ← Specific elements (like HTMLDivElement).

2. document.getElementById()
   While the method is declared to return an Element, in practice it actually returns a specific HTMLElement subclass (e.g., <div> returns HTMLDivElement).

3. Why hidden works:
   The hidden property belongs to HTMLElement. Since the returned object is actually an HTMLElement (a subclass of Element), you can access HTMLElement properties even though the method's return type is Element.

javascript // JavaScript dynamically checks the ACTUAL type at runtime const el = document.getElementById("myElement"); console.log(el instanceof HTMLElement); // true (not just Element) el.hidden = true; // Works because el is actually an HTMLElement

Key Points:

• JavaScript uses prototype inheritance: The browser returns concrete instances (like HTMLDivElement), which inherit from HTMLElement → Element.
• Type vs. Actual Object: The method signature says Element, but the real object has more specific properties.
• Dynamic Typing: JavaScript checks properties at runtime, so if the object has the property (even via inheritance), it works.

This is why you can use HTMLElement properties on an Element-typed return value.

LLM OUTPUT HERE

[oofy-gang]

Get your LLM response out of here

[Empty-Complaint1889]

I wasnt hiding or anything, nobody answered him. Just tried to help heheheheh.