A Simple Voting Smart Contract – Step‑by‑Step

1. Install and Set Up MetaMask

Why: MetaMask manages accounts and signs transactions. It bridges your browser to Ethereum networks (Ganache in this HW).

1. Install the MetaMask browser extension from the official site/store.
2. Open MetaMask → create a new wallet → securely store the recovery phrase.
3. After setup, you will see your first account (e.g., Account 1).

2. Set Up Ganache

Why: Ganache simulates an Ethereum network locally. No real money needed.

1. Download and install Ganache (GUI) from Truffle Suite.
2. Open Ganache → Quickstart Ethereum.
3. Ganache creates 10 accounts with 100 ETH each. RPC runs at http://127.0.0.1:7545.

3. Connect MetaMask to Ganache

Why: MetaMask must point to your local blockchain to deploy and send transactions.

1. In MetaMask, open the network selector → Add Network → Add a network manually.
2. Fill in:
   • Network Name: Ganache
   • New RPC URL: http://127.0.0.1:7545
   • Chain ID: 1337
   • Currency Symbol: ETH
3. Save, then switch MetaMask to the Ganache network.

4. Import a Ganache Account into MetaMask

Why: Use a prefunded Ganache account to pay for deployments.

1. In Ganache, click the key icon for the first account → copy its private key.
2. In MetaMask: account icon → Import Account → paste the private key → Import.

5–7. Open Remix, Write, Compile, and Deploy

5. Open Remix and Write the Contract

1. Open Remix IDE in your browser.
2. New file → Voting.sol → paste the code below.

Copy// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract Voting {
    string[] public candidateList;
    mapping(string => uint256) public votesReceived;

    constructor(string[] memory candidateNames) {
        candidateList = candidateNames;
    }

    function voteForCandidate(string memory candidate) public {
        require(validCandidate(candidate), "Candidate does not exist");
        votesReceived[candidate] += 1;
    }

    function totalVotesFor(string memory candidate) public view returns (uint256) {
        require(validCandidate(candidate), "Candidate does not exist");
        return votesReceived[candidate];
    }

    function validCandidate(string memory candidate) public view returns (bool) {
        for (uint i = 0; i < candidateList.length; i++) {
            if (keccak256(abi.encodePacked(candidateList[i])) == keccak256(abi.encodePacked(candidate))) {
                return true;
            }
        }
        return false;
    }
}

6. Compile the Contract

1. Click Solidity Compiler in Remix sidebar.
2. Set compiler to 0.8.0 or higher.
3. Click Compile Voting.sol. Look for the green checkmark.

7. Deploy to Ganache

1. Click Deploy & Run Transactions in Remix.
2. Environment: choose Injected Web3 (connects to MetaMask). (Alternatively, you may use Remix VM (Cancun) for practice, but homework requires Ganache.)
3. Ensure MetaMask is on the Ganache network.
4. Constructor args: ["Alice", "Bob", "Charlie"]
5. Click Deploy → confirm the MetaMask transaction.

8–10. Interact with the Contract

8. Cast a Vote

1. Expand the deployed Voting instance in Remix.
2. Find voteForCandidate. Enter "Alice" (quotes included; case‑sensitive).
3. Click the function → confirm in MetaMask.

9. Validate a Candidate

1. Find validCandidate.
2. Enter "Bob" and click. Result appears below: true or false.

10. Count Votes

1. Find totalVotesFor.
2. Enter "Alice" and click to read the current vote count.

Troubleshooting

• MetaMask not connecting: Ensure the network RPC URL is http://127.0.0.1:7545 and Chain ID 1337. Switch accounts if needed.
• Deployment fails: Confirm MetaMask is on Ganache and Ganache is running. Check Injected Web3 is selected in Remix.
• Wrong constructor input: Ensure array syntax and quotes are correct: ["Alice", "Bob", "Charlie"].
• Function calls revert: Names are case‑sensitive; run validCandidate first to verify.
• Out of gas / high gas: Use default Remix gas limits; Ganache has ample balance.