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

Type conversion


By now, we know that Solidity is a statically typed language, where variables are defined with specific data types at compile time. The data type cannot be changed for the lifetime of the variable. It means it can only store values that are legal for a data type. For example, uint8 can store values from 0 to 255. It cannot store negative values or values greater than 255. Take a look at the following code to better understand this:

However, there are times when these conversions are required to copy a value into a variable of one type to another, and these are called type conversions. Solidity provides rules for type conversions.

In Solidity, we can perform various kinds of conversion and we will cover these in the following sections.

Implicit conversion

Implicit conversion means that there is no need for an operator, or no external help is required for conversion. These types of conversion are perfectly legal and there is no loss of data or mismatch of values. They are completely...