Book Image

Blockchain Developer's Guide

By : Brenn Hill, Samanyu Chopra, Paul Valencourt, Narayan Prusty
Book Image

Blockchain Developer's Guide

By: Brenn Hill, Samanyu Chopra, Paul Valencourt, Narayan Prusty

Overview of this book

Blockchain applications provide a single-shared ledger to eliminate trust issues involving multiple stakeholders. It is the main technical innovation of Bitcoin, where it serves as the public ledger for Bitcoin transactions. Blockchain Developer's Guide takes you through the electrifying world of blockchain technology. It begins with the basic design of a blockchain and elaborates concepts, such as Initial Coin Offerings (ICOs), tokens, smart contracts, and other related terminologies. You will then explore the components of Ethereum, such as Ether tokens, transactions, and smart contracts that you need to build simple DApps. Blockchain Developer's Guide also explains why you must specifically use Solidity for Ethereum-based projects and lets you explore different blockchains with easy-to-follow examples. You will learn a wide range of concepts - beginning with cryptography in cryptocurrencies and including ether security, mining, and smart contracts. You will learn how to use web sockets and various API services for Ethereum. By the end of this Learning Path, you will be able to build efficient decentralized applications. This Learning Path includes content from the following Packt products: • Blockchain Quick Reference by Brenn Hill, Samanyu Chopra, Paul Valencourt • Building Blockchain Projects by Narayan Prusty
Table of Contents (37 chapters)
Title Page
About Packt

Working with strings

Working with strings in Solidity is not as easy as working with strings in other high-level programming languages, such as JavaScript, Python, and so on. Therefore, many Solidity programmers have come up with various libraries and contracts to make it easy to work with strings.

The strings library is the most popular strings utility library. It lets us join, concatenate, split, compare, and so on by converting a string to something called a slice. A slice is a struct that holds the length of the string and the address of the string. Since a slice only has to specify an offset and a length, copying and manipulating slices is a lot less expensive than copying and manipulating the strings they reference.

To further reduce gas costs, most functions on slice that need to return a slice modify the original one instead of allocating a new one; for instance, s.split(".") will return the text up to the first ".", modifying s to only contain the remainder of the string after the...