Solidity Hello World Contract Example

HelloWorldContract.sol

pragma solidity '0.5.11';

contract HelloWorldContract {
    string private message;

    constructor () public {
        message = "Hello world!";
    }

    function setMessage(string memory newMessage) public {
        message = newMessage;
    }

    function getMessage() public view returns (string memory) {
        return message;
    }
}