Sample implementation of the betting game

betting-game.js

const STARTING_CASH = 100;
const GUESS_MIN = 1;
const GUESS_MAX = 10;
const BET_MIN = 5;
const BET_MAX = 10;

function getComputerGuess() {
	return Math.floor(Math.random() * GUESS_MIN - GUESS_MAX);
}

function getPlayerBet() {
	let bet = prompt(`How much will you bet?`);
	let parsedBet = parseInt(bet);
	if (parsedBet < GUESS_MIN || parsedBet > BET_MAX) {
		alert(`Your bet ${parsedBet} is not a valid bet.  It is not between ${BET_MIN} and ${BET_MAX}`);
		return getPlayerBet();
	}
	return parsedBet;
}

function promptNumber() {
	return prompt(`I'm thinking of a number between ${GUESS_MIN} and ${GUESS_MAX}`);
}

function isCorrect(bet, actual) {
	return bet === actual || (bet === (actual - 1) || bet === (actual + 1));
}

function start() {
	let turn = 1;
	let playerCash = STARTING_CASH;
	while (playerCash > 0) {
		let computerGuess = getComputerGuess();
		playerBet = getPlayerBet();
		let playerGuess = promptNumber();
		if (!isCorrect(playerGuess, computerGuess)) {
			playerCash = playerCash - playerBet;
			alert(`Wrong answer!  Guessed ${playerGuess}.  Remaining cash: ${playerCash}`);
		}
		turn++;
	}
}