Book Image

Solidity Programming Essentials

Book Image

Solidity Programming Essentials

Overview of this book

Solidity is a contract-oriented language whose syntax is highly influenced by JavaScript, and is designed to compile code for the Ethereum Virtual Machine. Solidity Programming Essentials will be your guide to understanding Solidity programming to build smart contracts for Ethereum and blockchain from ground-up. We begin with a brief run-through of blockchain, Ethereum, and their most important concepts or components. You will learn how to install all the necessary tools to write, test, and debug Solidity contracts on Ethereum. Then, you will explore the layout of a Solidity source file and work with the different data types. The next set of recipes will help you work with operators, control structures, and data structures while building your smart contracts. We take you through function calls, return types, function modifers, and recipes in object-oriented programming with Solidity. Learn all you can on event logging and exception handling, as well as testing and debugging smart contracts. By the end of this book, you will be able to write, deploy, and test smart contracts in Ethereum. This book will bring forth the essence of writing contracts using Solidity and also help you develop Solidity skills in no time.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

How are contracts deployed?


Remix makes deployment of contracts a breeze; however, it is performing a lot of steps behind the scenes. It is always useful to understand the process of deploying contracts to have finer control over the deployment process.

The first step is the compilation of contracts. The compilation is done using the Solidity compiler. The next chapter will show you how to download and compile a contract using the Solidity compiler.

The compiler generates the following two major artifacts:

  • ABI definition 
  • Contracts bytecode

Think of the Application Binary Interface (ABI) as an interface consisting of all external and public function declarations along with their parameters and return types. The ABI defines the contract and any caller wanting to invoke any contract function can use the ABI to do so.

The bytecode is what represents the contract and it is deployed in the Ethereum ecosystem. The bytecode is required during deployment and ABI is needed for invoking functions in a contract.

A new instance of a contract is created using the ABI definition.

Deploying a contract itself is a transaction. A transaction is created for deploying the contract on Ethereum. The bytecode and ABI are necessary inputs for deploying a contract.

As any transaction execution costs gas in Euthereum, appropriate quantity of gas should be supplied while deploying the contract. As and when the transaction is mined, the contract is would be available for interaction through contract address.

Using the newly generated address, callers can invoke functions within the contract.