LinkedList.js

class LinkedList{
    constructor() {
        this.head = null
    }

    remove(i) {

    }
    insert(val, i) {
        const node = {
            value: val,
            next: null
        }
        let current = this.head
        if (current !== null){
            for(let j = 0; j < i; j++) {
                current = current.next
            }
            if (current !== null) {
                node.next = current.next
                current.next = node
            }
        } else {
            this.head = node
        }
    }
    print() {
        let current = this.head

        while(current !== null) {
            console.log(current.value)
            current = current.next
        }
        console.log('end')
    }
}

const x = new LinkedList()

x.insert(2, 0)
x.print()
x.insert(3, 1)
x.print()
x.insert(1, 0)
x.print()
x.insert(4, 3)
x.print()