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

Function input and output

Functions would not be that interesting if they didn't accept parameters and return values. Functions are made generic with the use of parameters and return values. Parameters can help by changing function execution and providing different execution paths. Solidity allows you to accept multiple parameters within a function; the only condition is that their identifiers should be uniquely named.

We will use the following code listing to understand functions and their different flavors of input parameters and return values:

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;; 
contract Parameters {
     function SingleIncomingParameter(int _data) public 
       pure returns (int _output) {
          return _data * 2;
     }
     function MultipleIncomingParameter(int _data...