Book Image

Building Blockchain Projects

By : Narayan Prusty
Book Image

Building Blockchain Projects

By: Narayan Prusty

Overview of this book

Blockchain is a decentralized ledger that maintains a continuously growing list of data records that are secured from tampering and revision. Every user is allowed to connect to the network, send new transactions to it, verify transactions, and create new blocks, making it permission-less. This book will teach you what blockchain is, how it maintains data integrity, and how to create real-world blockchain projects using Ethereum. With interesting real-world projects, you will learn how to write smart contracts which run exactly as programmed without any chance of fraud, censorship, or third-party interference, and build end-to-e applications for blockchain. You will learn about concepts such as cryptography in cryptocurrencies, ether security, mining, smart contracts, solidity, and more. You will also learn about web sockets, various API services for Ethereum, and much more. The blockchain is the main technical innovation of bitcoin, where it serves as the public ledger for bitcoin transactions.
Table of Contents (16 chapters)
Title Page
About the Author
About the Reviewers
Customer Feedback

What are the different data types?

Solidity is a statically typed language; the type of data a variable holds needs to be predefined. By default, all bits of the variables are assigned to 0. In Solidity, variables are function scoped; that is, a variable declared anywhere within a function will be in scope for the entire function regardless of where it is declared.

Now let's look at the various data types provided by Solidity:

  • The most simple data type is bool. It can hold either true or false.
  • uint8, uint16, uint24 ... uint256 are used to hold unsigned integers of 8 bits, 16 bits, 24 bits ... 256 bits, respectively. Similarly, int8, int16 ... int256 are used to hold signed integers of 8 bits, 16 bits ... 256 bits, respectively. uint and int are aliases for uint256 and int256. Similar to uint and int, ufixed and fixed represent fractional numbers. ufixed0x8, ufixed0x16 ... ufixed0x256 are used to hold unsigned fractional numbers of 8 bits, 16 bits ... 256 bits, respectively. Similarly, fixed0x8...