Decentralized Voting

Decentralized voting refers to a voting system that operates on a blockchain. The key idea here is to leverage the transparency, security, and immutability provided by blockchain technology to build a voting system that is hard to manipulate and easy to verify.

In a decentralized voting system, each vote is a transaction on the blockchain that can be seen by all participants but can only be modified by the voter till the vote is cast. Once a vote is cast, it’s recorded on the blockchain and cannot be altered, providing a transparent and tamper-proof voting mechanism.

Introduction to Remix IDE

Remix IDE (Integrated Development Environment) is a powerful, open-source tool designed specifically for Ethereum smart contract development. It runs directly in your web browser, so you don’t need to install anything on your computer.

You can access the Remix IDE at https://remix.ethereum.org. When you open Remix in your browser, you’ll find three panels:

1. Left Panel: This is where you can create, import, and manage your Solidity files. It also includes various plugins for compiling, testing, debugging, and deploying your contracts.

2. Central Panel: This is your code editor. Here you will write and edit your Solidity code.

3. Right Panel: This panel provides various tools to compile your contracts, deploy them on the Ethereum network (either on a real Ethereum network or a JavaScript VM simulation), and interact with your deployed contracts.

Your First Smart Contract

Let’s start with a simple “Voter” contract. This contract will keep track of voters in our system.

In the Remix IDE, go to “File Explorer” and click on the “+” icon to create a new file. Name it Voter.sol.

Now, let’s start writing our contract:

Solidity
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;

contract Voter {
    // A struct to represent a person
    struct Person {
        bool voted;  // if true, that person already voted
        uint vote;   // index of the voted proposal
    }

    // A mapping to keep track of all voters
    mapping(address => Person) public voters;

    // A function to register a voter
    function registerVoter() public {
        voters[msg.sender].voted = false;
    }
}

1. SPDX License Identifier: The // SPDX-License-Identifier: GPL-3.0 line indicates that our contract uses the GNU General Public License v3.0. This is a commonly used free software license that guarantees end users the freedom to run, study, share, and modify the software.

2. Pragma Directive: The pragma solidity >=0.7.0 <0.9.0; statement specifies that the contract is written in a version of Solidity that is greater or equal to 0.7.0 and less than 0.9.0. It helps prevent the contract from being compiled with a newer, incompatible compiler version.

3. Contract Definition: The contract Voter {...} block defines a new contract named Voter. This is where we specify the state variables and functions of the contract.

4. Struct Definition: Inside the contract, we define a struct Person that represents a person in our voting system. Each Person has a voted boolean that indicates if they have already voted and a vote integer that keeps track of the proposal they voted for.

5. State Variable: The mapping(address => Person) public voters; statement declares a state variable voters that creates a link between an Ethereum address and a Person struct. This will allow us to keep track of who is eligible to vote in the system and what their vote is. The public keyword automatically creates a getter function for voters.

6. Function Definition: The function registerVoter() public {...} block defines a public function that allows users to register themselves as voters in the system. The voters[msg.sender].voted = false; statement sets the voted status of the new voter to false.
   That’s it for this contract! As we progress through the course, we will expand this contract by adding more functions for the voting process. Remember to regularly compile and test your code to ensure that everything is working as expected. In the Remix IDE, you can compile your contract by clicking on the Solidity compiler icon on the left sidebar (the third one from the top) and then clicking on the “Compile” button.

In the next lesson, we’ll learn how to allow registered voters to cast votes and implement the logic for a voting system. But for now, play around with the contract and familiarize yourself with the Remix environment. You’ve just taken your first step into the world of smart contract development!