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

Arrays


Arrays are discussed as data types but, more specifically they are data structures that are dependent on other data types. Arrays refer to groups of values of the same type. Arrays help in storing these values together and ease the process of iterating, sorting, and searching for individuals or subsets of elements within this group. Solidity provides rich array constructs that cater to different needs.

An example of an array in Solidity is as follows:

uint[5] intArray ;

Arrays in Solidity can be fixed or dynamic.

Fixed arrays

Fixed arrays refer to arrays that have a pre-determined size mentioned at declaration. Examples of fixed arrays are as follows:

int[5] age ; // array of int with 5 fixed storage space allocated
byte[4] flags ; // array of byte with 4 fixed storage space allocated

Fixed arrays cannot be initialized using the new keyword. They can only be initialized inline, as shown in the following code:

int[5] age = [int(10), 20,30,40,50] ;

They can also be initialized inline within...