Book Image

Blockchain for Enterprise

By : Narayan Prusty
Book Image

Blockchain for Enterprise

By: Narayan Prusty

Overview of this book

The increasing growth in blockchain use is enormous, and it is changing the way business is done. Many leading organizations are already exploring the potential of blockchain. With this book, you will learn to build end-to-end enterprise-level decentralized applications and scale them across your organization to meet your company's needs. This book will help you understand what DApps are and how the blockchain ecosystem works, via real-world examples. This extensive end-to-end book covers every blockchain aspect for business and for developers. You will master process flows and incorporate them into your own enterprise. You will learn how to use J.P. Morgan’s Quorum to build blockchain-based applications. You will also learn how to write applications that can help communicate enterprise blockchain solutions. You will learn how to write smart contracts that run without censorship and third-party interference. Once you've grasped what a blockchain is and have learned about Quorum, you will jump into building real-world practical blockchain applications for sectors such as payment and money transfer, healthcare, cloud computing, supply chain management, and much more.
Table of Contents (14 chapters)
Title Page
Packt Upsell

Features of contracts

It is time to delve more deeply into contracts. Let's start with some new features and then we will go deeper into the features we have already seen.


The visibility of a state variable or a function defines who can see it. There are four kinds of visibility: external, public, internal, and private.

By default, the visibility of functions is public and the visibility of state variables is internal. Let's see what these visibility functions mean:

  • external: External functions can only be called from other contracts or via transactions. For example, we cannot call an f external function internally: f() will not work but this.f() will. We also cannot apply external visibility to state variables.
  • public: Public functions and state variables can be accessed in every possible way. Compiler-generated accessor functions are all public state variables. It is not possible to create our own accessors. Actually, it generates only getters, not setters.
  • internal: Internal functions...