Search⌘ K
AI Features
Home
Courses
Recursion for Coding Interviews in JavaScript

Solution Review: Length of a Linked List

Explore how to calculate the length of a linked list using a recursive function. Learn the base and recursive cases with a step-by-step code walkthrough to deepen your understanding of recursion with linked data structures.

We'll cover the following...

Solution: Using Recursion

Javascript (babel-node)
import LinkedList from './linkedList.js'
function length(testVariable, head) {
	// Base case
	if (head == null) {
		return 0;
	}
		
	// Recursive case
	else {
		return 1 + length(testVariable, head.next); 
	}
}
// Driver Code
var list = new LinkedList();
list.appendNode(4); 
list.appendNode(3); 
list.appendNode(11); 
list.appendNode(7); 
console.log(length(list, list.head))

Explanation

Have a look at the function length() in index.js file.

The base case (line number 5 to 7) for this problem is when a linked list contains no nodes. In this case, we return 00 as the length of that linked list.

For the recursive case (line number 11), we move the head pointer to its next node, head.next, and call another instance of the same function recursively. When this child function returns, we add 11 to the result.

Our solution is based on the following premise: ...