import java.util.Scanner;
public class BlackJack {
static Scanner stdin = new Scanner(System.in);
static String[] deck = new String[52];
static String dealerCard = "", dealerHiddenCard = "", userCard = "", userCardTwo = "";
static int dealerCounter = 0, userCounter = 0;
public static void main (String[] args) {
System.out.println("\n***Welcome to the grand Command Line Casino!***" +
"\n***Today we are only playing single deck Black Jack!***" +
"\n***But that's what we do everyday! HAHA!***\n");
//Creates Deck of cards
String[] suit = { "Clubs", "Diamonds", "Hearts", "Spades" };
String[] rank = { "2", "3", "4", "5", "6", "7", "8", "9", "10",
"Jack", "Queen", "King", "Ace" };
for (int a=0; a < rank.length; a++) {
for (int b=0; b < suit.length; b++){
deck[suit.length*a + b] = (rank[a] +" of "+ suit[b]);
}
}
//Assigns two cards to the dealer
//Finds the Integer value of each card and adds it to the dealerCounter
//first dealer card
System.out.println("----Dealer's Cards:----");
System.out.println("(Dealer's First Card Placed Face Down)");
dealerHiddenCard = randomCard(dealerHiddenCard);
dealerCard = assignValue(dealerHiddenCard);
dealerCounter = Integer.parseInt(dealerCard);
//second dealer card
dealerCard = randomCard(dealerCard);
System.out.println(dealerCard);
dealerCard = assignValue(dealerCard);
dealerCounter += Integer.parseInt(dealerCard);
//Assigns two cards to the user
//Finds the Integer value of each card and adds it to the userCounter
//first user card
System.out.println("\n----Your Cards:----");
userCardTwo = randomCard(userCardTwo);
System.out.println(userCardTwo);
userCardTwo = assignValue(userCardTwo);
userCounter = Integer.parseInt(userCardTwo);
//second user card
userCard = randomCard(userCard);
System.out.println(userCard);
userCard = assignValue(userCard);
userCounter += Integer.parseInt(userCard);
/////// HERES ONE /////////
/////// HERES ONE /////////
userAceHandler(userCounter);
/////// HERES ONE /////////
/////// HERES ONE /////////
if (userCounter == 21) {
System.out.println("Black Jack! You Win!"); }
hitStay();
dealersTurn();
}
public static String randomCard(String draw) {
//Pulls a random card from the deck
while (true) {
//Generates a random number between 0 and 52
int card = (int)(Math.random()*52);
draw = deck[card];
//Makes sure the same card isn't drawn twice
if (draw == "0") {
continue;}
else {
deck[card] = "0";
return draw;}
}
}
public static String assignValue(String cardName) {
//Assigns a number value to the card
if (cardName.contains("2")) {
cardName = "2"; }
if (cardName.contains("3")) {
cardName = "3"; }
if (cardName.contains("4")) {
cardName = "4"; }
if (cardName.contains("5")) {
cardName = "5"; }
if (cardName.contains("6")) {
cardName = "6"; }
if (cardName.contains("7")) {
cardName = "7"; }
if (cardName.contains("8")) {
cardName = "8"; }
if (cardName.contains("9")) {
cardName = "9"; }
if (cardName.contains("10")) {
cardName = "10"; }
if (cardName.contains("Jack")) {
cardName = "10"; }
if (cardName.contains("Queen")){
cardName = "10"; }
if (cardName.contains("King")) {
cardName = "10"; }
if (cardName.contains("Ace")) {
cardName = "11"; }
return cardName;
}
public static void hitStay() {
//Processes a user 'Hit or Stay' selection
int userInput;
System.out.println("\nHit or Stay?");
System.out.println("(1) Hit\n(2) Stay");
userInput = stdin.nextInt();
if (userInput == 1){
//Draws another card and adds it to the userCounter
//Decides where to go depending on new userCounter value
userCard = randomCard(userCard);
System.out.println("\n"+userCard);
userCard = assignValue(userCard);
userCounter += Integer.parseInt(userCard);
/////// HERES ONE /////////
/////// HERES ONE /////////
userAceHandler(userCounter);
/////// HERES ONE /////////
/////// HERES ONE /////////
System.out.print("(Current Count = "+userCounter+")");
if (userCounter == 21) {
System.out.println("\n21! Now it's the dealer's turn");
}
if (userCounter < 21) {
hitStay(); }
if (userCounter > 21) {
System.out.println("Bust! Maybe next time");
System.exit(1); }
}
if (userInput == 2){
System.out.println("\nAlright, dealer's turn");
System.out.println("\n(Dealer Flips His Hidden Card Over)");
System.out.println(dealerHiddenCard);
System.out.println("Dealer Count = "+dealerCounter+")");
}
}
public static void dealersTurn() {
//processes the dealers turn after the user has decided to 'stay'
/////// HERES ONE /////////
/////// HERES ONE /////////
dealerAceHandler(dealerCounter);
/////// HERES ONE /////////
/////// HERES ONE /////////
if (dealerCounter > userCounter) {
System.out.println("\nDealer Wins! Maybe next time."); }
System.exit(1);
if (dealerCounter == userCounter && dealerCounter > 17) {
System.out.println("\nPush! (tie game)");
System.exit(1); }
if (dealerCounter > userCounter && dealerCounter < 21
&& dealerCounter >= 17) {
System.out.println("\nDealer Wins! Maybe next time.");
System.exit(1); }
if (dealerCounter < userCounter && dealerCounter >= 17) {
System.out.println("\nYou Win!");
System.exit(1); }
if (dealerCounter > 21) {
System.out.println("\nDealer Bust! You Win!");
System.exit(1); }
if (dealerCounter == 21) {
System.out.println("\nDealer Wins! Maybe next time.");
System.exit(1); }
if (dealerCounter < userCounter || dealerCounter < 17) {
dealerCard = randomCard(dealerCard);
System.out.println("\n"+dealerCard);
dealerCard = assignValue(dealerCard);
dealerCounter += Integer.parseInt(dealerCard);
System.out.println("(Dealer Count = "+dealerCounter+")");
dealersTurn(); }
}
public static int userAceHandler(int userCounter) {
//handles the situation if an Ace is drawn for the user
if (userCounter >= 22 && userCard == "11") {
userCounter = userCounter - 10;
return userCounter; }
}
public static int dealerAceHandler(int dealerCounter) {
//handles the situation if an Ace is drawn for the dealer
if (dealerCounter >= 22 && dealerCard == "11") {
dealerCounter = dealerCounter - 10;
return dealerCounter; }
}
}
好的！我今天花了大约10个小时制作这个（它是一个基本的二十一点游戏），并且在添加代码底部的最后两个方法之前我已经完美地工作了。他们要在我的代码中处理'Ace'条件......不幸的是，当我尝试编译时，它告诉我，我错过了两者的return语句。我只有5周的编程生涯和一周的“我自己的方法”生涯，所以我没有线索。我以为我做对了。
我会用大量的笔记标记，我称之为方法（每个位置只有3个点）
就像我说的那样，在我添加这些内容之前，它与其他所有内容完美配合。
非常感谢您的帮助！
答案 0 :(得分：9)
你做在return函数中有userAceHandler个语句，但这还不够。如果if条件不正确怎么办？在这种情况下没有return声明。 Java要求您为非return函数中的每个可能的代码路径提供void语句。
答案 1 :(得分：3)
问题是，在java方法中，你必须总是返回一些东西。只有条件完成后，您的方法才会返回值。你必须返回一些东西，即使它不是。尽量在最后写return 0;或类似的东西。
答案 2 :(得分：1)
正如所讨论的，最好的解决方案是移动return语句
public static int dealerAceHandler(int dealerCounter) {
if (dealerCounter >= 22 && dealerCard == "11") {
dealerCounter = dealerCounter - 10;
}
return dealerCount;
}
- 原创 - 由于您正在编辑函数的输入，可能只是使方法签名无效而不返回任何内容
注意，您必须使用一个对象来执行此操作，因为Java是通过引用传递的，除了基元
public static void dealerAceHandler(Integer dealerCounter) {
if (dealerCounter >= 22 && dealerCard == "11") {
dealerCounter = dealerCounter - 10;
}
}
否则返回在if语句内，因此如果不满足条件则不返回值