javascript自定义数据结构

HashMap

折叠代码块JAVASCRIPT 复制代码

HashMap () {
  // Map 大小
  var size = 0
  // 对象
  var entry = {}

  // 存
  this.put = function (key, value) {
    if (!this.containsKey(key)) {
      size++
    }
    entry[key] = value
  }

  // 取
  this.get = function (key) {
    return this.containsKey(key) ? entry[key] : null
  }

  // 删除
  this.remove = function (key) {
    if (this.containsKey(key) && (delete entry[key])) {
      size--
    }
  }

  // 是否包含 Key
  this.containsKey = function (key) {
    return (key in entry)
  }

  // 是否包含 Value
  this.containsValue = function (value) {
    for (var prop in entry) {
      if (entry[prop] === value) {
        return true
      }
    }
    return false
  }

  // 所有 Value
  this.values = function () {
    var values = []
    for (var prop in entry) {
      values.push(entry[prop])
    }
    return values
  }

  // 所有 Key
  this.keys = function () {
    var keys = []
    for (var prop in entry) {
      keys.push(prop)
    }
    return keys
  }

  // Map Size
  this.size = function () {
    return size
  }

  // 清空
  this.clear = function () {
    size = 0
    entry = {}
  }
  // 根据 Value 获取key
  this.getKeyByValue = function (value) {
    for (var prop in entry) {
      if (entry[prop] === value) {
        return prop
      }
    }
    return null
  }
}