HierarchyChecker.java

package RockPaperScissors;

public class HierarchyChecker {
    /**
     * Checks to see who won a match by using the rock, paper, scissors hierarchy:
     * <p>-Rock beats scissors
     * <p>-Scissors beat paper
     * <p>-Paper beats rock
     * @param playerOne a String that represents the object chosen by playerOne or the user
     *                  ("r" for rock, "p" for paper, "s" for scissors)
     * @param playerTwo a String that represents the object chosen by playerTwo or generated by
     *                  the npc ("r" for rock, "p" for paper, "s" for scissors)
     * @return a boolean that represents who won (true for playerOne/user, false for playerTwo/npc)
     */
    public static boolean whoWon(String playerOne, String playerTwo) {
        switch (playerOne) {
            //if user entered rock:
            case "r" : {
                //if the npc entered paper: they win, if the npc entered scissors: they lose
                switch (playerTwo) {
                    case "p" : return false; //npc won
                    case "s" : return true; //user won
                }
            }
            //if the user entered paper
            case "p" : {
                //if the npc entered rock: the lose, if the npc entered scissors: they win
                switch (playerTwo) {
                    case "r" : return true; //user won
                    case "s" : return false; //npc won
                }
            }
            //if the user entered scissors
            case "s" : {
                //if the npc entered rock: they win, if the npc entered paper: they lose
                switch (playerTwo) {
                    case "r" : return false; //npc won
                    case "p" : return true; //user won
                }
            }
        }

        //this return statement will not be reached because playerOne/user's object has been
        //checked and is valid and playerTwo/npc's object has been checked and is valid
        return false;
    }
}