js单链表的封装

class Node {
            constructor(element) {
                this.element = element
                this.next = null
            }
        }
        class LinkedList {
            constructor() {
                this.count = 0
                this.head = null
            }
            push(element) {
                const node = new Node(element)
                if (this.head === null) {
                    this.head = node
                } else {
                    let current = this.head
                    while (current.next !== null) {
                        current = current.next
                    }
                    current.next = node
                }
                this.count++
            }
            //指定位置删除
            removeAt(index) {
                if (index >= 0 && index < this.count) {
                    let current = this.head
                    if (index === 0) {
                        this.head = this.head.next
                    } else {
                        let previous = this.getNodeAt(index - 1)
                        current = this.getNodeAt(index)
                        previous.next = current.next
                    }
                    this.count--
                    return current.element
                }
                return
            }
            //获取指定下标的节点
            getNodeAt(index) {
                if (index >= 0 && index < this.count) {
                    let node = this.head
                    for (let i = 0; i < index; i++) {
                        node = node.next
                    }
                    return node
                }
                return
            }
            equalFn(a, b) {
                return JSON.stringify(a) === JSON.stringify(b)

            }
            indexOf(element) {
                let current = this.head
                for (let i = 0; i < this.count; i++) {
                    if (this.equalFn(element, current.element)) {
                        return i
                    }
                    current = current.next
                }
                return -1
            }
            //删除指定元素
            remove(element) {
                const index = this.indexOf(element)
                return this.removeAt(index)
            }
            insert(element, index) {
                if (index >= 0 && index <= this.count) {
                    const node = new Node(element)
                    if (index === 0) {
                        let current = this.head
                        node.next = current
                        this.head = node
                    } else {
                        let previous = this.getNodeAt(index - 1)
                        let current = previous.next
                        node.next = current
                        previous.next = node
                    }
                    this.count++
                    return true
                }
                return false
            }
            isEmpty() {
                return this.size() === 0
            }
            size() {
                return this.count
            }
            getHead() {
                return this.head
            }
        }
        let link = new LinkedList()