Simple Linked List in TypeScript.

linked-list.ts

const VecNode = (value?: any) => ({
  value,
  next: null
})

function Vec() {
  let _node = VecNode()
  let length = 0

  return {
    _node,
    get(idx: number) {
      let n = this._node

      if (idx > length + 1) return null

      for (let i = 0; i < idx; i++) {
        if (!n) return null

        n = n.next
      }

      if (!n) return null

      return n.value
    },
    toString() {
      let idx = length
      let str = ''
      let n = this._node

      if (idx > length + 1) return null

      for (let i = 0; i < idx; i++) {
        str += `${n.value}${i === idx - 1 ? '' : ', '}`

        n = n.next
      }

      return `Vec(${str})`
    },
    inspect() {
      return this.toString()
    },
    length,
    push(item) {
      if (length === 0) {
        _node.value = item
        return length++
      }

      _node.next = VecNode(item)
      _node = _node.next

      return length++
    },
    pop() {
      let idx = length - 1
      const item = this.get(idx)

      let n = this._node

      if (idx > length + 1) return null

      for (let i = 0; i < idx - 1; i++) {
        n = n.next
      }

      n.next = null

      if (length > 0) {
        length--
      }

      if (length === 0) {
        _node.value = null

        return item
      }

      _node = n

      if (!n) return null

      return item
    }
  }
}

const v = Vec()
v

v.push(5)
v

v.push(10)
v

v.get(0) //?

v.push(20)
v //?

v.length //?
v

v.pop() //?
v

v.get(0) //?
v.get(1) //?

v.push(30)

v.get(0) //?
v.get(1) //?
v.get(2) //?

v.get(3) //?
v.get(4) //?

v.pop() //?
v.pop() //?
v.pop() //?
v.pop() //?

v.push('SSJ')
v.push('112')
v