Book Image

Ethereum Smart Contract Development

By : Mayukh Mukhopadhyay
Book Image

Ethereum Smart Contract Development

By: Mayukh Mukhopadhyay

Overview of this book

Ethereum is a public, blockchain-based distributed computing platform featuring smart contract functionality. This book is your one-stop guide to blockchain and Ethereum smart contract development. We start by introducing you to the basics of blockchain. You'll learn about hash functions, Merkle trees, forking, mining, and much more. Then you'll learn about Ethereum and smart contracts, and we'll cover Ethereum virtual machine (EVM) in detail. Next, you'll get acquainted with DApps and DAOs and see how they work. We'll also delve into the mechanisms of advanced smart contracts, taking a practical approach. You'll also learn how to develop your own cryptocurrency from scratch in order to understand the business behind ICO. Further on, you'll get to know the key concepts of the Solidity programming language, enabling you to build decentralized blockchain-based applications. We'll also look at enterprise use cases, where you'll build a decentralized microblogging site. At the end of this book, we discuss blockchain-as-a-service, the dark web marketplace, and various advanced topics so you can get well versed with the blockchain principles and ecosystem.
Table of Contents (18 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Increment and decrement operations using Solidity


Figure 3.10 shows the code of an increment and decrement operation in Solidity. It also has a function that takes input, and a function, that fetches out this number once the contract gets executed:

Figure 3.10: Increment and decrement operation using Solidity (ArithValue.sol)

Isn't this code a bit more complex than the hello world contract? Let me walk you through this code. The first line starts with pragma. As you have realized already, it just states which version of Solidity we are about to use. In our case, we are using version 0.4.11. As I type, remix IDE supports versions up to 0.4.16.

To understand pragma, let us go back to our brunch buffet analogy from Chapter 2, Grokking Ethereum. If I specify during the buffet reservation that I am a strict vegan, I am giving the buffet organizers some sort of directive, in advance, that I do not eat non-vegan dishes like meat, fish, poultry, or eggs. So, I get introduced to only those counters...