coding_challenge_4b.js

class Node{
    constructor(val){
        this.val = val
        this.next = null;
    }
}

function listContains(root, val){
    let curr = root;
    while(curr){
        if(curr.val == val) return true;
        curr = curr.next;
    }
    return false;
}

const Amy     = new Node("Amy");
const Barry   = new Node("Barry");
const Cameron = new Node("Cameron");

Amy.next   = Barry;
Barry.next = Cameron;

console.log(listContains(Amy, "Cameron")); // true
console.log(listContains(Amy, "Jenny"));   // false