About Queue Data Structure

Question

Hello Guys I know it is not the good way to write Queue but I want to understand this thing

here in my code I have a Node Class and there is just (int data and Node Next) inside it.

in other class, I am doing this

Node head = new Node(1);
            head.next = new Node(2);
            head.next.next = new Node(3);
           
            Node temp = head;
            temp.next.next.next = new Node(4);

 Console.WriteLine(head.data + "\n" + head.next.data + "\n" + head.next.next.data + "\n"+head.next.next.next.data);

I am getting this output.

1
2
3
4

I want to understand why head printing found the last node which I create in Temp

can someone understand me and tell me why?

Node Temp just copied head and added a new Node which is 4 but what makes this last node appear in head?.

Answer 1

You need to understand the reference types for this. So a class/object is a reference type .

A reference type ,extends System.Object and points to a location in the memory that contains the actual data.

So when you said Node temp=head`.

Now both of the object point to same location and any changes in one will change the other

https://www.tutlane.com/tutorial/csharp/csharp-value-type-and-reference-type-with-examples

https://www.infoworld.com/article/3043992/a-deep-dive-value-and-reference-types-in-net.html

So first of all new keyword always creates new object.So as you can see temp and head are same when you assign head= temp

As soon as you say , temp=temp.next, now it will point to next node and now head and temp will not be same.Temp will point to the next node of head

Now as soon as you write temp = new Node("10");it creates new object and assign to temp.So new key word always creates new object

But if you do like this temp.Data="10" without doing temp=new Node("10");, it will change both head and temp

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