// Specifies that the source code is for a version of Solidity of exactly 0.8.0 pragma solidity 0.8.0; // A contract is a collection of functions and data (its state) // that resides at a specific address on the Ethereum blockchain. contract HelloWorld { // The keyword "public" makes variables accessible from outside a contract // and creates a function that other contracts or SDKs can call to access the value string public message; // A special function only run during the creation of the contract constructor(string memory initMessage) public { // Takes a string value and stores the value in the memory data storage area, // setting `message` to that value message = initMessage; } // A publicly accessible function that takes a string as a parameter // and updates `message` function update(string memory newMessage) public { message = newMessage; } }