Book Image

Learn Blockchain Programming with JavaScript

By : Eric Traub
Book Image

Learn Blockchain Programming with JavaScript

By: Eric Traub

Overview of this book

Learn Blockchain Programming with JavaScript begins by giving you a clear understanding of what blockchain technology is. You’ll then set up an environment to build your very own blockchain and you’ll add various functionalities to it. By adding functionalities to your blockchain such as the ability to mine new blocks, create transactions, and secure your blockchain through a proof-of-work you’ll gain an in-depth understanding of how blockchain technology functions. As you make your way through the chapters, you’ll learn how to build an API server to interact with your blockchain and how to host your blockchain on a decentralized network. You’ll also build a consensus algorithm and use it to verify data and keep the entire blockchain network synchronized. In the concluding chapters, you’ll finish building your blockchain prototype and gain a thorough understanding of why blockchain technology is so secure and valuable. By the end of this book, you'll understand how decentralized blockchain networks function and why decentralization is such an important feature for securing a blockchain.
Table of Contents (10 chapters)

Creating a genesis block

One more thing that we would have to add to our blockchain data structure is the genesis block. But what is a genesis block? Well, a genesis block is simply the first block in any blockchain.

To create our genesis block, we are going to use the createNewBlock method inside of the Blockchain() constructor function. Go to the dev/blockchain.js file, and inside of the blockchain constructor function type in the following highlighted lines of code:

function Blockchain () {
this.chain = [];
this.pendingTransactions =[];

As we observed in the previous section, the createNewBlock method takes in the value of a nonce, a previousBlockHash, and a hash as parameters. Since we're using the createNewBlock method over here to create the genesis block, we are not going to have any of those mentioned parameters. Instead...