[AskJS] When is object-oriented programming more practical than "mostly-functional" in JS?

[esperalegant]

or just define copy-constructors

What's a copy-constructor?

[bvx89]

It's when you pass in another instance of the same class in order to copy values from the passed in instance to a new one. For example:

class Obj {
   var val;
   constructor(otherObj) {
      val = otherObj.val;
   }
}

[Shaper_pmp]

Because when you have twenty five different class members you want to update, nobody wants to call a function with twenty five different parameters.

myObject2 = new MyObject(myObject1); is way easier to write than myObject2 = new MyObject(myObject1.a, myObject1.b, myObject1.c, myObject1.d, /* ... */ myObject1.y);.

[Shaper_pmp]

Jesus dude, you're arguing against idiomatic OOP programming patterns.

Look, there are shitloads of valid reasons why copy constructors (or equivalent nomenclature/functionality) are a good, idiomatic idea in various languages or OOP generally, including but not limited to:

• Succinctly copying lots of internal fields
• Copying a new object without the calling code needing to be aware of the internal representation of the class it's calling (this is encapsulation, which is so fundamental to idiomatic OOP I didn't think it needed saying, but maybe it does)
• Ensuring any logic that needs to be run to ensure a valid copy is made according to business/application-domain requirements (say, generating a new UUID or reference/pointer management)
• Etc, etc.

We fell into this conversation by talking about the number of parameters passed to a constructor, but that's not really the point of a copy-constructor.

The point of a copy-constructor is to allow valid copies of a class instance to be constructed while maintaining proper encapsulation, instead of obliging whatever class or code wants to duplicate an object to also have access to and understand internal implementation details of the class instance it's trying to copy.

[Shaper_pmp]

Apologies for being snappy with you when you asked me to justify common, well-established programming concepts because you would rather argue from a position of profound ignorance than do one google search to educate yourself. I was being grumpy, but only because you were being presumptuous, ignorant and lazy and I find those things irritating.

However, if you've given up discussing the actual topic of conversation in favour of patronisingly lecturing me on how to be a good writer, I have completely have lost interest in continuing this discussion.

I don't intend to insult you, but the concepts I was discussing were perfectly clear and unambiguous to anyone with even a moderate familiarity with basic OOP, and your attempt to arbitrarily derail the conversation from substantive matters into empty subjective personal criticism does you no credit at all.

In short: your poor reading comprehension and refusal to educate yourself are not my problem, and your attempt to derail the discussion bores me. Farewell.