Creating Sample Blockchain using NodeJS

//DemoBlockchain.js
const SHA256=require('crypto-js/sha256');
class Block
{
    constructor(index,data)
    {
        this.index=index;
        this.data=data;
        this.timestamp=Date.now();
        this.pHash='';
        this.hash=this.hashing();
    }
    hashing()
    {
        return SHA256(this.index+this.timestamp+this.pHash+JSON.stringify(this.data)).toString();
    }
}
class Blockchain
{
    constructor()
    {
        this.chain=[this.genesicBlock()];
        this.nextIndex=1;
    }
    genesicBlock()
    {
        return new Block(0,"Genesis Block");
    }
    getLatestBlock()
    {
        return this.chain[this.chain.length-1];
    }
    insertBlock(newBlock)
    {
        newBlock.pHash=this.getLatestBlock().hash;
        newBlock.hash=newBlock.hashing();
        this.chain.push(newBlock);
        this.nextIndex++;
    }
    getIndex()
    {
        return this.nextIndex;
    }
    isTemperedWith()
    {
        for(let i=1;i<this.chain.lenght;i++)
        {
            const currentBlock=this.chain[i];
            const previousBlock=this.chain[i-1];
            if(currentBlock.hash!=currentBlock.hashing() || currentBlock.pHash !=previousBlock.hash)
             return true;
        }
        return false;
    }
}


let coin=new Blockchain();
coin.insertBlock(new Block(coin.getIndex(),{Amount:10}));
coin.insertBlock(new Block(coin.getIndex(),{Amount:45}));
coin.insertBlock(new Block(coin.getIndex(),{Amount:354}));

console.log(JSON.stringify(coin,null,2));
console.log('\nBlockchain : '+coin.isTemperedWith());
coin.chain[1].data={Data:1000};
coin.chain[1].hash=coin.chain[1].hashing();
console.log('Blockchain hacked '+coin.isTemperedWith());


//  Dependency
//  "crypto-js": "^3.1.9-1"

// How to run a blockchain
// npm init
// node DemoBlockchain.js