Book Image

The Essential Guide to Web3

By : Vijay Krishnan
3 (1)
Book Image

The Essential Guide to Web3

3 (1)
By: Vijay Krishnan

Overview of this book

Web3, the new blockchain-based web, is often hailed as the future of the internet. Driven by technologies such as cryptocurrencies, NFTs, DAOs, decentralized finance, and more, Web3’s aim is to give individuals more control over the web communities they belong to. Whether you’re a beginner or an experienced developer, this book will help you master the intricacies of Web3 and its revolutionary technologies. Beginning with a concise introduction to blockchain and the Ethereum ecosystem, this book quickly immerses you in real-world blockchain applications. You’ll work on carefully crafted hands-on exercises that are designed for beginners as well as users with prior exposure. The chapters show you how to build and deploy smart contracts, while mastering security controls and discovering best practices for writing secure code. As you progress, you’ll explore tokenization and gain proficiency in minting both fungible and non-fungible tokens (NFTs) with the help of step-by-step instructions. The concluding chapters cover advanced topics, including oracles, Layer 2 (L2) networks, rollups, zero knowledge proofs, and decentralized autonomous organizations (DAOs). By the end of this Web3 book, you’ll be well-versed in the Web3 ecosystem and have the skills to build powerful and secure decentralized applications.
Table of Contents (25 chapters)
Free Chapter
1
Part 1 – Introduction to Web3
5
Part 2 – All about Smart Contracts
9
Part 3 – Writing Your DApps for Web3
12
Part 4 – Fungible Tokens
15
Part 5 – Non-Fungible Tokens
18
Part 6 – Web3 Advanced Topics

Understanding a Hello World smart contract

“Hello World” is quite a simple contract and the best one for beginners to smart contract coding and Solidity. You will find that this example is commonly used by new users to get acquainted with Solidity smart contracts.

Here is an example of a HelloWorld smart contract in Solidity, along with a detailed explanation of each line:

pragma solidity ^0.9.0;contract HelloWorld {
    string greeting;
    constructor() {
        greeting = "Hello, World!";
    }
    function greet() public view returns (string memory) {
        return greeting;
    }
}

Let us go through each line:

  • pragma solidity ^0.9.0;: This is a pragma version that specifies which version of Solidity the contract uses. The caret symbol (^) indicates that the...