pragma solidity >=0.4.22 <0.6.0; contract Mortal { /* Define variable owner of the type address */ address owner; /* This constructor is executed at initialization and sets the owner of the contract */ constructor() public { owner = msg.sender; } /* Function to recover the funds on the contract */ function kill() public { if (msg.sender == owner) selfdestruct(msg.sender); } } contract Greeter is Mortal { /* Define variable greeting of the type string */ string greeting; /* This runs when the contract is executed */ constructor(string memory _greeting) public { greeting = _greeting; } /* Main function */ function greet() public view returns (string memory) { return greeting; } } 0.4.25