Rock-Paper-Scissors.js

var selection = ["Rock", "Paper", "Scissors"];
var player = playerChoice();
var computer = computerChoice();

console.log(compare(player, computer));

function playerChoice() {
	var choice;
	 do {
        choice = prompt("Rock(1), Paper(2), or Scissors(3)?").toLowerCase();
        switch(choice) {
        	case 'rock':
        		choice = 1;
        		break;
        	case 'paper':
        		choice = 2;
        		break;
        	case 'scissors':
        		choice = 3;
        		break;
        	default:
        		choice = parseInt(choice);
        }
    } while (choice !== 1 && choice !== 2 && choice !== 3);
  
	console.log("Player Choice: " + selection[choice - 1] + ".")
	return choice;
}

function computerChoice() {
	var choice = Math.floor(Math.random() * 3 + 1);
	console.log("Computer Choice: " + selection[choice - 1] + ".");
	return choice;
}

function compare(player, computer) {
	switch(player) {
		case 1:
			switch(computer) {
				case 1:
					return "The game resulted in a tie.";
				case 2:
					return "The computer won.";
				case 3:
					return "You won.";
			}
			break;
		case 2:
			switch(computer) {
				case 1:
					return "You won.";
				case 2:
					return "The game resulted in a tie.";
				case 3:
					return "The computer won.";
			}
			break;
		case 3:
			switch(computer) {
				case 1:
					return "The computer won.";
				case 2:
					return "You won.";
				case 3:
					return "The game resulted in a tie.";
			}
			break;
	} 
}