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

Solidity expressions


An expression refers to a statement (comprising multiple operands and optionally zero or more operators) that results in a single value, object, or function. The operand can be a literal, variable, function invocation, or another expression itself.

An example of an expression is as follows:

Age > 10

In the preceding code, Age is a variable and 10 is an integer literal. Age and 10 are operands and the (>) greater than symbol is the operator. This expression returns a single boolean value (true or false) depending on the value stored in Age.

Expressions can be more complex comprising multiple operands and operators, as follows:

((Age > 10) && (Age < 20) ) || ((Age > 40) && (Age < 50) )

In the preceding code, there are multiple operators in play. The && operator acts as an AND operator between two expressions, which in turn comprises operands and operators. There is also an OR operator represented by the || operator between two complex...