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Blockchain for Enterprise

You're reading from  Blockchain for Enterprise

Product type Book
Published in Sep 2018
Publisher Packt
ISBN-13 9781788479745
Pages 220 pages
Edition 1st Edition
Languages
Concepts
Author (1):
Narayan Prusty Narayan Prusty
Profile icon Narayan Prusty

Table of Contents (14) Chapters

Title Page
Packt Upsell
Contributors
Preface
1. What are Decentralized Applications? 2. Building Blockchain Using Quorum 3. Writing Smart Contracts 4. Getting Started with web3.js 5. Building Interoperable Blockchains 6. Building Quorum as a Service Platform 7. Building a DApp for Digitizing Medical Records 8. Building a Payment Solution for Banks 1. Other Books You May Enjoy Index

The structure of a smart contract


A is akin to a class. It can functions, modifiers, state variables, events, structures, and enums. Contracts also support inheritance. You can implement inheritance by copying code during compiling. Smart contracts can also be polymorphic.

The following an example of a smart contract:

contract Sample
{
     //state variables 
     uint256 data;
     address owner;

     //event definition
     event logData(uint256 dataToLog);

     //function modifier
     modifier onlyOwner() {
         if (msg.sender != owner) throw;
         _; 
    }

     //constructor
     function Sample(uint256 initData, address initOwner){
         data = initData;
         owner = initOwner;
     }

     //functions
     function getData() returns (uint256 returnedData){
         return data;
     }
     function setData(uint256 newData) onlyOwner{
         logData(newData);
         data = newData;
     }
}

Let's see how the aforementioned code works:

  • First, we used the contract...
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