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

Polymorphism


Polymorphism means having multiple forms. There are the following two types of polymorphism:

  • Function polymorphism
  • Contract polymorphism

Function polymorphism

Function polymorphism refers to declaring multiple functions within the same contract or inheriting contracts having the same name. The functions differ in the parameter data types or in the number of parameters. Return types are not taken into consideration for determining valid function signatures for polymorphism. This is also known as method overloading.

The next code segment illustrates a contract that contains two functions, which have the same name but different data types for incoming parameters. The first function, getVariableData, accepts int8 as its parameter data type, while the next function having the same name accepts int16 as its parameter data type. It is absolutely legal to have the same function name with a different number of parameters of different data types for incoming parameters as shown in the following...