Linked List Brief Intro:
- Linear collection data structure
- Chain of nodes ⛓ - "each node contains a value and a pointer to the next node in the chain."
Singly Linked List (one direction only)
1 -> 2 -> 3 -> 4 -> null (when the pointer gets to null, it has reached the end of the linked list)
^
Head: beginning of the linked list
//Linked List Node Class Declaration
class ListNode {
constructor(value = 0, next = null) {
this.value = value;
this.next = next;
}
}
In this Linked List series, I will be using curr (stands for current) as the main pointer to move through a Linked List.
//Using curr allows us to remember the head to return it at the end of the function
let curr = head;
1 -> 2 -> 3 -> 4 -> null
^
curr
curr = ListNode {
value: 1,
next: ListNode {
value: 2,
next: ListNode {
value: 3,
next: ListNode {
value: 4,
next: null
}
}
}
}
curr.value = 1
1 -> 2 -> 3 -> 4 -> null
^ ->
curr.next (the next node based on the current node)
curr.next = ListNode{2, ListNode{3, ListNode{4}}}
curr.next.value = 2
How to move to the next node in a Linked List?
//assigning curr to the next node
curr = curr.next;
Here is an example:
while(curr) { //keep iterating as long as curr is not null
curr = curr.next;
}
While 'curr' is not null:
1 -> 2 -> 3 -> 4 -> null
^ ->
curr.value = 1
curr.next.value = 2
curr = curr.next;
__
While 'curr' is not null:
1 -> 2 -> 3 -> 4 -> null
^ ->
curr.value = 2
curr.next.value = 3
curr = curr.next;
__
While 'curr' is not null:
1 -> 2 -> 3 -> 4 -> null
^ ->
curr.value = 3
curr.next.value = 4
curr = curr.next;
__
While 'curr' is not null:
1 -> 2 -> 3 -> 4 -> null
^ ->
curr.value = 4
curr.next = null
curr = curr.next;
__
1 -> 2 -> 3 -> 4 -> null
^ ->
'curr' is null, stop the iteration.
The pointer has now moved through the entire Linked List.
References & Additional Resources:
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