Book Image

Solidity Programming Essentials. - Second Edition

By : Ritesh Modi
Book Image

Solidity Programming Essentials. - Second Edition

By: Ritesh Modi

Overview of this book

Solidity is a high-level language for writing smart contracts, and the syntax has large similarities with JavaScript, thereby making it easier for developers to learn, design, compile, and deploy smart contracts on large blockchain ecosystems including Ethereum and Polygon among others. This book guides you in understanding Solidity programming from scratch. The book starts with step-by-step instructions for the installation of multiple tools and private blockchain, along with foundational concepts such as variables, data types, and programming constructs. You’ll then explore contracts based on an object-oriented paradigm, including the usage of constructors, interfaces, libraries, and abstract contracts. The following chapters help you get to grips with testing and debugging smart contracts. As you advance, you’ll learn about advanced concepts like assembly programming, advanced interfaces, usage of recovery, and error handling using try-catch blocks. You’ll also explore multiple design patterns for smart contracts alongside developing secure smart contracts, as well as gain a solid understanding of writing upgradable smart concepts and data modeling. Finally, you’ll discover how to create your own ERC20 and NFT tokens from scratch. By the end of this book, you will be able to write, deploy, and test smart contracts in Ethereum.
Table of Contents (21 chapters)
1
Part 1: The Fundamentals of Solidity and Ethereum
7
Part 2: Writing Robust Smart Contracts
13
Part 3: Advanced Smart Contracts

Abstract contracts

Abstract contracts are contracts that have partial function definitions. You cannot create an instance of an abstract contract. An abstract contract must be inherited by a child contract to utilize its functions.

Abstract contracts help in defining the structure of a contract, and any class inheriting from it must ensure to provide an implementation for them. If the child contract does not provide the implementation for incomplete functions, its instance cannot be created. The function signature is terminated using a semicolon (;). Solidity provides an abstract keyword to mark a contract as abstract. This is a relatively new keyword addition and it was not part of prior versions. A contract becomes an abstract contract when it consists of functions without any implementation.

The following code snippet is an implementation of an abstract contract.

The abstractHelloWorld contract is an abstract contract as it contains a couple of functions without any...