GAZAR

Principal Engineer | Mentor
Home
Algorithm
Hashing Algorithm

Hashing Algorithm

Hashing Algorithm

Hashing is a process of converting input data into a fixed-size value, typically a hash code or hash value, using a hash function. Hashing is widely used in various fields such as cryptography, data storage, and data retrieval due to its efficiency and effectiveness.

  • Deterministic Mapping: A hash function should produce the same hash value for the same input consistently.
  • Uniform Distribution: Ideally, hash values should be uniformly distributed across the hash space to minimize collisions.
  • Collision Handling: Collisions occur when two different inputs produce the same hash value. Hashing algorithms employ techniques to handle collisions efficiently, such as chaining or open addressing.
// Simple Hash Function (Modulo)
function simpleHash(key, size) {
    let hash = 0;
    for (let i = 0; i < key.length; i++) {
        hash = (hash + key.charCodeAt(i)) % size;
    }

    return hash;
}

// Hash Table Implementation
class HashTable {
    constructor(size) {
        this.size = size;
        this.table = Array.from({ length: size }, () => []);
    }

    insert(key, value) {
        const index = simpleHash(key, this.size);
        this.table[index].push({ key, value });
    }

    get(key) {
        const index = simpleHash(key, this.size);
        const bucket = this.table[index];
        for (const item of bucket) {
            if (item.key === key) {
                return item.value;
            }
        }

        return undefined;
    }
}


// Example usage:
const hashTable = new HashTable(10);
hashTable.insert("John", 25);
hashTable.insert("Alice", 30);
console.log("Value for key 'John':", hashTable.get("John"));
console.log("Value for key 'Alice':", hashTable.get("Alice"));

Comments