Hash Table

hash-table.js

// Source: https://www.section.io/engineering-education/hash-tables-in-javascript/#implementing-hash-tables-in-javascript%5D

class HashTable{
  constructor(size=50){
    this.buckets =  new Array(size)
    this.size = size
  }

  hash(key){
    return key.toString().length % this.size;
  }
  
  // Insert data
  setItem(key,value){
    let index = this.hash(key);
    
    if(!this.buckets[index]){
      this.buckets[index] = [];
    }
    
    this.buckets[index].push([key,value])
    return index
  }

  // Search data
  getItem(key){
    let index = this.hash(key);
  
     if(!this.buckets[index])return null
     
        for(let bucket of this.buckets[index]){
             // key
          if(bucket [0] === key){
             // value
            return bucket [1]
           }
        }
  }
}

const hashTable = new HashTable();
// Insert data to the hash table
hashTable.setItem("bk101","Data structures algorithms");
hashTable.setItem("bk108","Data analytics");
hashTable.setItem("bk200","Cyber security");
hashTable.setItem("bk259","Business Intelligence");
hashTable.setItem("bk330","S/W Development");

// Search data from the hash table 
hashTable.getItem("bk101");
console.log(hashTable.getItem("bk101"));