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

Chapter 13, Writing Secure Contracts 

  1. Msg.sender refers to the immediate caller while tx.origin refers to the original caller in chain. tx.origin is always an externally owned account whereas the msg.sender value can be a contract account or an externally owned account.
  2. Recursion happens because the receive function in the hacker contract calls the withdraw function, which, in turn, calls the receive function unknowingly because it transfers Ether to the hacker contract.
  3. Checks, effects, and the interaction pattern are three distinct stages in a sequence within a function that change the contract state and help transfer tokens and Ethers to other accounts securely. All incoming argument validation for correctness is executed as part of the check stage. This stage also includes validating the current state of the contract. By checking that the context and environment are at the conducive stage, the check stage ensures that nothing goes wrong from a state and incoming...