1. Introduction

In this tutorial, our goal is to guide you through the process of choosing the right blockchain platform for your project. Given the multitude of options available, this can be a daunting task. However, after reading this tutorial, you should be able to compare different blockchain platforms and make an informed decision based on the needs of your project.

You will learn about various blockchain platforms, their strengths and weaknesses, and how to evaluate them based on your project's requirements.

Prerequisites: Basic knowledge of blockchain technology and its applications.

2. Step-by-Step Guide

Understanding Your Project Requirements

Before you can choose a blockchain platform, you need to understand your project's needs. Here are some questions to consider:

• What is the purpose of your blockchain?
• Do you require a public or private blockchain?
• What level of security do you need?
• How important is scalability?
• What kind of consensus mechanism do you prefer?

Evaluating Blockchain Platforms

Different platforms have different strengths and weaknesses. Here are some popular platforms and what they are best for:

• Ethereum: The most popular platform for building decentralized applications (DApps). It is public and has a strong community.
• Hyperledger Fabric: A private, permissioned blockchain platform. It is highly modular and adaptable, suitable for enterprise use.
• Corda: A platform designed for the financial industry. It allows for private transactions and legal certainty.

3. Code Examples

While this tutorial doesn't involve coding, we will provide examples of how different platforms handle smart contracts, a crucial feature of blockchain applications.

Ethereum Smart Contract

// Version of Solidity compiler this program was written for
pragma solidity ^0.4.22;

// Our first contract is a simple one
contract HelloWorld {
    // Declares a state variable `message` of type `string`.
    string public message;

    // Similar to many class-based object-oriented languages, a constructor is
    // a special function that is only executed upon contract creation.
    constructor(string initialMessage) public {
        // Accepts a string input and stores it in the state variable `message`
        message = initialMessage;
    }

    // A function to change the `message`.
    function setMessage(string newMessage) public {
        message = newMessage;
    }
}

Hyperledger Fabric Chaincode

package main

import (
    "fmt"
    "github.com/hyperledger/fabric/core/chaincode/shim"
    sc "github.com/hyperledger/fabric/protos/peer"
)

type SmartContract struct {
}

func (s *SmartContract) Init(APIstub shim.ChaincodeStubInterface) sc.Response {
    return shim.Success(nil)
}

func (s *SmartContract) Invoke(APIstub shim.ChaincodeStubInterface) sc.Response {
    function, args := APIstub.GetFunctionAndParameters()
    if function == "query" {
        return s.query(APIstub, args)
    }
    return shim.Error("Invalid Smart Contract function name.")
}

func (s *SmartContract) query(APIstub shim.ChaincodeStubInterface, args []string) sc.Response {
    if len(args) != 1 {
        return shim.Error("Incorrect number of arguments. Expecting 1")
    }
    carAsBytes, _ := APIstub.GetState(args[0])
    return shim.Success(carAsBytes)
}

func main() {
    err := shim.Start(new(SmartContract))
    if err != nil {
        fmt.Printf("Error creating new Smart Contract: %s", err)
    }
}

4. Summary

In this tutorial, we've discussed what factors you need to consider when choosing a blockchain platform. We've also explored popular platforms and their strengths and weaknesses.

Next, you should dive deeper into the platform that seems most suitable for your project. Look at its documentation, check out sample projects, and try creating a simple application.

5. Practice Exercises

1. Write down a list of requirements for a hypothetical blockchain project. Consider factors like public vs private blockchain, level of security, and scalability.

2. Based on your list, choose one blockchain platform that seems to fit your requirements best. Write a short explanation of why you chose this platform.

3. If you chose Ethereum or Hyperledger Fabric, try writing a simple smart contract. If you chose another platform, explore its documentation and familiarize yourself with its key features.

Remember, the best way to learn is by doing. Don't be afraid to get your hands dirty and start coding!