Explore the beauty of India's undiscovered gems! India has some of the world's most beautiful gemstones: especially when it comes to flawless Golconda diamonds and the finest Kashmir sapphire. You'll soon find yourself mesmerised by the variety of gemstones to be found in this majestic country and spoilt for choice. It is great fun shopping for gemstones in India but (as with many other places in the world) you should remember one thing - buyer beware! Offering practical advice, tips and the essential questions to ask, Buying Gemstones and Jewellery in India will help you avoid the tricks of the trade on your holiday. Written by Kim Rix, a gemmologist (GIA) and professional photographer who has travelled to more than 50 countries in her lifetime, this essential guide for tourists is part of the Gemstone Detective series. It cuts through the jargon - for the benefit of hobbyists, gem collectors and jewellery lovers. Kim Rix is dedicated to visiting each country in the Gemstone Detective series to provide readers with up-to-date and trusted information. Without this book, you could make a very expensive mistake!

Discover the advanced features of Solidity that will help you write high-quality code and develop secure smart contracts with the latest ERC standards Key Features Delve into Solidity and understand control structures, function calls, and variable scopes Explore tools for developing, testing, and debugging your blockchain applications Learn advanced design patterns and best practices for writing secure smart contracts Book DescriptionSolidity is among the most popular and contract-oriented programming languages used for writing decentralized applications (DApps) on Ethereum blockchain. If you're looking to perfect your skills in writing professional-grade smart contracts using Solidity, this book can help. You will get started with a detailed introduction to blockchain, smart contracts, and Ethereum, while also gaining useful insights into the Solidity programming language. A dedicated section will then take you through the different Ethereum Request for Comments (ERC) standards, including ERC-20, ERC-223, and ERC-721, and demonstrate how you can choose among these standards while writing smart contracts. As you approach later chapters, you will cover the different smart contracts available for use in libraries such as OpenZeppelin. You'll also learn to use different open source tools to test, review and improve the quality of your code and make it production-ready. Toward the end of this book, you'll get to grips with techniques such as adding security to smart contracts, and gain insights into various security considerations. By the end of this book, you will have the skills you need to write secure, production-ready smart contracts in Solidity from scratch for decentralized applications on Ethereum blockchain. What you will learn Test and debug smart contracts with Truffle, Ganache, Remix, and MetaMask Gain insights into maintaining code quality with different tools Get up to speed with ERC standards such as ERC-20 and ERC-721 Become adept at using design patterns while writing smart contracts Use MultiSignature (MultiSig) wallets and improve the security of contracts Use Oracle services to fetch information from outside the blockchain Who this book is forThis book is for developers and data scientists who want to learn Ethereum, blockchain, and Solidity to write smart contracts and develop production-ready code. Basic knowledge of Solidity is assumed.

Understand Gang of Four, architectural, functional, and reactive design patterns and how to implement them on modern Java platforms, such as Java 12 and beyond Key Features Learn OOP, functional, and reactive patterns for creating readable and maintainable code Explore architectural patterns and practices for building scalable and reliable applications Tackle all kinds of performance-related issues and streamline development using design patterns Book DescriptionJava design patterns are reusable and proven solutions to software design problems. This book covers over 60 battle-tested design patterns used by developers to create functional, reusable, and flexible software. Hands-On Design Patterns with Java starts with an introduction to the Unified Modeling Language (UML), and delves into class and object diagrams with the help of detailed examples. You'll study concepts and approaches to object-oriented programming (OOP) and OOP design patterns to build robust applications. As you advance, you'll explore the categories of GOF design patterns, such as behavioral, creational, and structural, that help you improve code readability and enable large-scale reuse of software. You'll also discover how to work effectively with microservices and serverless architectures by using cloud design patterns, each of which is thoroughly explained and accompanied by real-world programming solutions. By the end of the book, you'll be able to speed up your software development process using the right design patterns, and you'll be comfortable working on scalable and maintainable projects of any size. What you will learn Understand the significance of design patterns for software engineering Visualize software design with UML diagrams Strengthen your understanding of OOP to create reusable software systems Discover GOF design patterns to develop scalable applications Examine programming challenges and the design patterns that solve them Explore architectural patterns for microservices and cloud development Who this book is forIf you are a developer who wants to learn how to write clear, concise, and effective code for building production-ready applications, this book is for you. Familiarity with the fundamentals of Java is assumed.