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 7. Functions, Modifiers, and Fallbacks

Solidity is maturing and providing advanced programming constructs so that users can write better smart contracts. This chapter is dedicated to some of the most important smart contract constructs, such as functions, modifiers, and fallbacks. Functions are the most important element of a smart contract after state variables. It is functions that help to create transactions and implement custom logic in Ethereum. There are various types of functions, which will be discussed in depth in this chapter. Modifiers are special functions that help in writing more readily available and modular smart contracts. Fallbacks are a concept unique to contract-based programming languages, and they are executed when a function call does not match any existing declared method in the contract. Finally, every function has visibility attached to it that affects its availability to the external caller, other contracts, and contracts in inheritance.

This chapter covers...