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

Interfaces


Interfaces are like abstract contracts, but there are differences. Interfaces cannot contain any definition. They can only contain function declarations. It means functions in interfaces cannot contain any code. They are also known as pure abstract contracts. An interface can contain only the signature of functions. It also cannot contain any state variables. They cannot inherit from other contracts or contain enums or structures. However, interfaces can inherit other interfaces. The function signatures terminate using the semicolon ; character. Interfaces are declared using the interface keyword following by an identifier. The next code example shows an implementation of the interface. Solidity provides the interface keyword for declaring interfaces. The IHelloWorld interface is defined containing two function signatures—GetValue and SetValue. There are no functions containing any implementation. IHelloWorld is implemented by the HelloWorld contract. Contract intent to use this...