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

Variable scoping

Scoping refers to the availability of a variable within a function and a contract in Solidity. Solidity provides the following two locations where variables can be declared:

  • Contract-level global variables (also known as state variables)
  • Function-level local variables

It is quite easy to understand function-level local variables. They are only available anywhere within a function and not outside.

Contract-level global variables are variables that are available to all functions, including constructors, fallbacks, and modifiers within a contract. Contract-level global variables can have a visibility modifier attached to them. It is important to understand that state data can be viewed across an entire network, irrespective of the visibility modifier. The following state variables can only be modified using functions:

  • public: These state variables are accessible directly from external calls. A getter function is implicitly generated by the...