22.04 Code Quasi-connectivity (Stack n heap)

This article is about code, not about Minecraft:

I stole the name from it though.

Stack n Heap

What is it?

Ever had something like the following scenario happening to you:

const list1 = [1,1];
const list2 = list1;
list2[1] = 5;
console.log(list1) // [1,5]
console.log(list2) // [1,5]

But at the same time, the following works differently:

const num1 = 1;
const num2 = num1;
num2 = 5;
console.log(num1) // 1
console.log(num2) // 5

This is a thing which happens in most programming languages. The real name of this is “Stack and heap”.

I call it Quasi-connectivity because it was magic to me just like the Minecraft Quasi-connectivity is to me. And Quasi-connectivity means that it is somehow linked, but not in a normal way.

Why is this?

Personally used this article to learn about this subject. But I’ll give a summary.

it is quite simple, whenever you register a variable it creates a memory address for it. It has to choose carefully where to put it in memory though, because you don’t want to overwrite memory when the value becomes too big. This is why it registers the maximum space in the memory for the variable, and gets the memory address for it. And then when the code gets a memory address, it reads it’s value, and uses it.

But when you register an object, array, dictionary, the code can’t calculate the maximum size, because they can be theoretically endless. So what it does in memory is create a list of references, which point towards the variables of the object. and then the code will receive a memory address pointing towards the list of references.

And displaying the actual value happens seamlessly in your programming language, but when you try to copy it, this is what is actually happening:

const list1 = [1,1]; // list1 = 0x7FFFA1234BCD
const list2 = list1; // list2 = list1, AKA 0x7FFFA1234BCD

The reason why this is happening to objects is because they have 2 layers of memory addresses, and the computer compensates 1 whenever the code tells it to load a variable.

Minecraft Quasi-connectivity

Yeah no I am not going to explain this. This article is not about Minecraft.

Go Figure