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Learn Blockchain Programming with JavaScript

You're reading from   Learn Blockchain Programming with JavaScript Build your very own Blockchain and decentralized network with JavaScript and Node.js

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Product type Paperback
Published in Nov 2018
Publisher Packt
ISBN-13 9781789618822
Length 252 pages
Edition 1st Edition
Languages
Concepts
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Author (1):
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Eric Traub Eric Traub
Author Profile Icon Eric Traub
Eric Traub
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Table of Contents (10) Chapters Close

Preface 1. Setting up the Project 2. Building a Blockchain FREE CHAPTER 3. Accessing the Blockchain through an API 4. Creating a Decentralized Blockchain Network 5. Synchronizing the Network 6. Consensus Algorithms 7. Block Explorer 8. In conclusion... 9. Other Books You May Enjoy

Building the chainIsValid method

Let's start building the consensus algorithm by creating a new method called chainIsValid. This method will validate whether or not a chain is legitimate. Let's get started with building this method:

  1. In the blockchain.js file, after the proofOfWork method, let's define the method as follows:
Blockchain.prototype.chainIsValid = function() {

}
  1. Now, this method will take in a blockchain as an argument, and will return to us whether the blockchain is valid or not:
Blockchain.prototype.chainIsValid = function(blockchain) {

}

We're going to use this chainIsValid method to validate the other chains inside of the network when we are comparing them to the chain that is hosted on the current node. In order to validate that the blockchain is legitimate, we're simply going to iterate through every block inside of the blockchain...

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