Bryant Nielson | May 15, 2023
This smart contract allows two players to place a bet on a number between 1 and 100. One player can choose the winning number, and then both players can place their bets. If a player guesses the winning number, they win the bet and the contract will pay out the winnings. The contract also has a function to end the game and pay out to the winner.
pragma solidity ^0.6.0;
contract Bet {
// Declare variables
address payable public player1;
address payable public player2;
uint public betAmount;
uint public winningNumber;
bool public player1Wins;
bool public player2Wins;
bool public gameOver;
// Constructor function – runs when contract is deployed
constructor(address payable _player1, address payable _player2, uint _betAmount) public {
player1 = _player1;
player2 = _player2;
betAmount = _betAmount;
}
// Function to place a bet
function placeBet(uint _guess) public payable {
require(!gameOver, “The game is over, no more bets allowed”);
require(msg.value == betAmount, “The bet must be for the agreed upon amount”);
require(_guess >= 1 && _guess <= 100, “The guess must be between 1 and 100”);
if (_guess == winningNumber) {
if (msg.sender == player1) {
player1Wins = true;
} else {
player2Wins = true;
}
gameOver = true;
}
}
// Function to choose the winning number
function chooseWinningNumber(uint _winningNumber) public {
require(!gameOver, “The game is over, the winning number cannot be changed”);
require(msg.sender == player1 || msg.sender == player2, “Only player 1 or 2 can choose the winning number”);
require(_winningNumber >= 1 && _winningNumber <= 100, “The winning number must be between 1 and 100”);
winningNumber = _winningNumber;
}
// Function to end the game and pay out to the winner
function endGame() public {
require(gameOver, “The game is not over yet”);
if (player1Wins) {
player1.transfer(2 * betAmount);
} else if (player2Wins) {
player2.transfer(2 * betAmount);
}
}
}
One does not necessarily need to be a programmer to understand the construction of a Smart Contract. In the above example can you:
Write down the sequence of steps that the Smart Contract follows.
What happens if the number is not guessed?
Can the 2 parties independently select the amount of bet?
