#Add integer to list java constructor code

If you use it for primitive types be sure to use the nullable class equivalents (ex 'Integer' for the 'int' type). Basically, this linked list should work with any type that inherits from Object. The 'T' type is a generic type placeholder. Note: It's a pretty basic implementation of a singly-linked-list. You then construct a new LinkNode here, set it's value, and add it to the LinkedList. When you add an item in the LinkedList, you traverse all the LinkNode's until you reach the last one. A LinkedList just has a special LinkNode reference that refers to the first item in the list. Yes, it's a self referential data structure.

For this assignment, you want to create two classes: LinkNodeĪ LinkNode has one member field for the data it contains, and a LinkNode reference to the next LinkNode in the LinkedList. What you have coded is not a LinkedList, at least not one that I recognize. Scheme is probably the most well known example of a language with this feature.

#Add integer to list java constructor code

This makes such code completely avoid using the stack, which makes it safer (you can't overflow the stack if you don't use the stack) and typically more efficient. * Some languages have tail call elimination, which is an optimization that lets the language implementation convert 'tail calls' (a call to another function as the very last step before returning) into (effectively) a 'goto'. You can turn that into an iterative solution which would be more efficient in Java *, and wouldn't risk a stack overflow with very long lists, but I'm guessing that level of complexity isn't needed for your assignment. This is the recursive approach, which is the least amount of code.

If next isn't null, then append to next instead. If it is, create a new one element list and set next to that. This would be for creating a 1-element list. You may want to add another constructor that just takes a String, and sets next to null. So you can treat next as just another list that happens to be one element shorter. That list of 1 element has a word ('Overflow') and an empty list ( null). The list of 2 elements has a word ('Stack') and a list of 1 element. Note that it's a LinkedList object pointing to a word ('Hello') and a list of 2 elements. Here's a diagram of a LinkedList containing 3 elements: In fact, many similar implementations use the name 'tail' instead of 'next'. Think of next as being 'the rest of the list'. With this kind of setup you'd use null for when you need an empty list. With your LinkedList class, an instance will always be a list of at least one element. What you're doing is more appropriate for a class assignment. The Collections API linked list is also a doubly linked list, while you're building a singly linked list.

The Collections API is trying to adhere to a more complicated interface. There are some differences between the way you're creating a linked list and the way the Java collections API does it. It's good to understand how things work, and understanding linked lists is an important step towards understanding more complex data structures, many of which don't exist in the standard libraries. That said, don't think of this as a pointless exercise. I am only allowed to use 'new', variable declarations, and assignment statements.If you're actually building a real system, then yes, you'd typically just use the stuff in the standard library if what you need is available there. I am supposed to write the constructor in a way that allows me to create a linked list with three nodes without using any method calls. The professor did not give me any big hints with this, and I am struggling to satisfy the guidelines he issued. For an assignment, I have to write a constructor for a double linked list.