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

Chapter 8. Exceptions, Events, and Logging

Writing contracts is the fundamental purpose of Solidity. However, writing a contract demands sound error and exception handling. Errors and exceptions are the norm in programming and Solidity provides ample infrastructure for managing both. Writing robust contracts with proper error and exception management is one of the top best practices. Events are another important construct in Solidity. For all topics that we've discussed so far, we've seen a caller that invokes functions in contracts; however we have not discussed any mechanism through which a contract notifies its caller and others about changes in its state and otherwise. This is where events come in. Events are a part of event-driven programs where, based on changes within a program, it proactively notifies its caller about the changes. The caller is free to use this information or ignore it. Finally, both exceptions and events, to a large extent, use the logging feature provided by EVM...