Book Image

Blockchain Developer's Guide

By : Brenn Hill, Samanyu Chopra, Paul Valencourt, Narayan Prusty
Book Image

Blockchain Developer's Guide

By: Brenn Hill, Samanyu Chopra, Paul Valencourt, Narayan Prusty

Overview of this book

Blockchain applications provide a single-shared ledger to eliminate trust issues involving multiple stakeholders. It is the main technical innovation of Bitcoin, where it serves as the public ledger for Bitcoin transactions. Blockchain Developer's Guide takes you through the electrifying world of blockchain technology. It begins with the basic design of a blockchain and elaborates concepts, such as Initial Coin Offerings (ICOs), tokens, smart contracts, and other related terminologies. You will then explore the components of Ethereum, such as Ether tokens, transactions, and smart contracts that you need to build simple DApps. Blockchain Developer's Guide also explains why you must specifically use Solidity for Ethereum-based projects and lets you explore different blockchains with easy-to-follow examples. You will learn a wide range of concepts - beginning with cryptography in cryptocurrencies and including ether security, mining, and smart contracts. You will learn how to use web sockets and various API services for Ethereum. By the end of this Learning Path, you will be able to build efficient decentralized applications. This Learning Path includes content from the following Packt products: • Blockchain Quick Reference by Brenn Hill, Samanyu Chopra, Paul Valencourt • Building Blockchain Projects by Narayan Prusty
Table of Contents (37 chapters)
Title Page
About Packt

Chapter 24. Writing Smart Contracts

In the previous chapter, we learned how the Ethereum blockchain works. Now it's time to start writing smart contracts as we have have a good grasp of how Ethereum works. There are various languages to write Ethereum smart contracts in, but Solidity is the most popular one. In this chapter, we will learn the Solidity programming language. We will finally build a DApp for proof of existence, integrity, and ownership at given a time, that is, a DApp that can prove that a file was with a particular owner at a specific time.

In this chapter, we'll cover the following topics:

  • The layout of Solidity source files
  • Understanding Solidity data types
  • Special variables and functions of contracts
  • Control structures
  • Structure and features of contracts
  • Compiling and deploying contracts