[数据结构与算法]JavaScript数据结构之哈希表的封装

    function HashTable() {
      this.storage = []
      this.count = 0
      this.limit = 7
      
      HashTable.prototype.hashFunc =  function(str, size) {
      var hashCode = 0
      for(var i = 0; i < str.length; i++){
        hashCode = 37 * hashCode + str.charCodeAt(i)
      }
      var index = hashCode % size
      return index
      }
      HashTable.prototype.put = function(key, value) {
        var index = this.hashFunc(key, this.limit)
        var bucket = this.storage[index]
        if (bucket == null) {
          bucket = []
          this.storage[index] = bucket
        }
        for (var i=0; i<bucket.length;i++) {
          var tuple = bucket[i]
          if (tuple[0] == key) {
            tuple[1] = value
            return
          }
        }
        bucket.push([key, value])
        this.count++
        if (this.count > this.limit * 0.75) {
          var newSize = this.limit*2
          var newPrime = this.getPrime(newsize)
          this.resize(newPrime)
        }
      }
      HashTable.prototype.get = function(key) {
        var index = this.hashFunc(key, this.limit)
        var bucket = this.storage[index]
        if (bucket == null) return null
        for(var i=0;i<bucket.length;i++) {
          var tuple = bucket[i]
          if (tuple[0] == key) return tuple[1]
        }
        return null
      }
      HashTable.prototype.delete = function(key) {
        var index = this.hashFunc(key, this.limit)
        var bucket = this.storage[index]
        if (bucket == null ) return null
        for(var i=0;i<bucket.length;i++) {
          var tuple = bucket[i]
          if (tuple[0] == key) {
            bucket.splice(i,1)
            this.count--
            return tuple[1]
            if (this.limit>7&&this.count<this.limit*0.25) {
              var newSize = Math.floor(this.limit/2)
              var newPrime = this.getPrime(newSize)
              this.resize(newPrime)
            }
          }
        }
        return null
      }
      HashTable.prototype.isEmpty = function() {
        return this.count == 0
      }
      HashTable.prototype.size = function() {
        return this.count
      }
      HashTable.prototype.resize = function(newLimit) {
        var oldStorage = this.storage
        this.storage = []
        this.count = 0
        this.limit = newLimit
        for (var i =0;i<oldStorage.length;i++){
          var bucket = oldStorage[i]
          if (bucket == null) {
            continue
          }
          for(var j=0;j<bucket.length;j++){
            var tuple = bucket[j]
            this.put(tuple[0],tuple[1])
          }
        }
      }
      HashTable.prototype.isPrime = function (num) {
      var temp = parseInt(Math.sqrt(num))
      for(var i = 2;i<= temp;i++){
        if (num%i==0) return false
      }
      return true
      }
      HashTable.prototype.getPrime = function(num) {
        while(!this.isPrime(num)) {
          num++
        }
        return num
      }
    }
    var ht = new HashTable()
    ht.put('abc','111')
    ht.put('eee','444')
    ht.delete('eee')
    console.log(ht);

完成了修改添加删除，实现了容量恒为质数