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

The byte data type


Byte refers to 8 bit signed integers. Everything in memory is stored in bits consisting of binary values—0 and 1. Solidity also provides the byte data type to store information in binary format. Generally, programming languages have a single data type for representing bytes. However, Solidity has multiple flavors of the byte type. It provides data types in the range from bytes1 to bytes32 inclusive, to represent varying byte lengths, as required. These are called fixed sized byte arrays and are implemented as value types. The bytes1 data type represents 1 byte and bytes2 represents 2 bytes. The default value for byte is 0x00 and it gets initialized with this value. Solidity also has a  byte type that is an alias to bytes1.

A byte can be assigned byte values in hexadecimal format, as follows:

bytes1 aa = 0x65;

A byte can be assigned integer values in decimal format, as follows:

bytes1 bb = 10;

A byte can be assigned negative integer values in decimal format, as follows:

bytes1...