how to create a hashtable in typescript which can store both number and string using generic code

running sample

https://stackblitz.com/edit/typescript-2zlayw


code=>

//hash node

class HashNode<T,U>

{

    key:T

    value:U

    constructor(_key:T,_value:U)

    {

        if(typeof _key==="object")

          throw new Error("object as key not allowed")

        this.key=_key;

        this.value=_value;

    }

    //get key

    public getKey()

    {

       return this.key;

    }

    //get value

    public getValue()

    {

       return this.value;

    }

}

//hash table

class HashTable<T,U>

{

   static TABLE_SIZE = 128;

    private table=[];

   //HashTable

   constructor()

   {

      for(let i=0;i<HashTable.TABLE_SIZE;i++)

      {

          this.table[i]=undefined

      }

   }

   //getHashIndex

   private getHashIndex(_key:T)

   {

     let hashIndex=0;

     if(typeof _key==="number")

     {

         hashIndex=_key%HashTable.TABLE_SIZE;

     }else

     {

        let hash=0

        for(let i=0;i<_key.length;i++)

        {

           hash+=_key[i].charCodeAt();     

        }

         hashIndex=hash%HashTable.TABLE_SIZE;

       

     }

       

   return hashIndex;

   }

   //Put

   public Put(_key:T,_value:U)

   {

       let hashIndex=this.getHashIndex(_key);

       while(this.table[hashIndex]!==undefined  && this.table[hashIndex].getKey()!==_key)

       {

         hashIndex=(hashIndex+1)%HashTable.TABLE_SIZE;

       }

       this.table[hashIndex]=new HashNode<T,U>(_key,_value);

   }  

   //get

   public Get(_key:T):any

   {

       let hashIndex=this.getHashIndex(_key);  

       while(this.table[hashIndex]!==undefined  && this.table[hashIndex].getKey()!=_key)

       {

         hashIndex=(hashIndex+1)%HashTable.TABLE_SIZE;

         if(this.table[hashIndex]===undefined)

           return -1;

       }

       return this.table[hashIndex].getValue();

   }

}

//create a hashtable number as a key

let hashtable=new HashTable<number,string>();

hashtable.Put(1,"apple");

hashtable.Put(2,"mango");

hashtable.Put(3,"banana");

hashtable.Put(7,"cheek");

console.log(hashtable.Get(7));

//create another hashtable string as key

let hashtable1=new HashTable<string,string>();

hashtable1.Put("face1","daragon");

hashtable1.Put("face2","appldaragon");

hashtable1.Put("face3","daragon22323");

hashtable1.Put("face2","manumanu");

console.log(hashtable1.Get("face2"))