我试图让变量walletMoney在用户获胜或失败时不断更新。我是java新手，有点困惑。我真的很感激解决方案和解释。谢谢。
/*
* This program will simulate playing a slot machine.
* It will provide instructions to the user with an initial stake of $50 and then let the user play until either the money runs out or the player quits.
* Author: Zac Saunders
* Version: 1.0
*/
import acm.program.*;
import acm.util.RandomGenerator;
public class SlotMachine extends ConsoleProgram {
RandomGenerator rgen = new RandomGenerator();
public int BAR_BAR_BAR = 250;
//The value that the user wins when he rolls a bar/bar/bar.
public int BELL_BELL_BELL = 20;
//The value that the user wins when he rolls a bell/bell/bell.
// BELL_BELL_BELL is the same as BELL_BELL_BAR.
public int PLUM_PLUM_PLUM = 14;
//The value that the user wins when he rolls a plum/plum/plum.
// PLUM_PLUM_PLUM is the same as PLUM_PLUM_BAR.
public int ORANGE_ORANGE_ORANGE = 10;
//The value that the user wins when he rolls an orange/orange/orange.
// ORANGE_ORANGE_ORANGE is the same as ORANGE_ORANGE_BAR;
public int CHERRY_CHERRY_CHERRY = 7;
//The value that the user wins when he rolls a cherry/cherry/cherry.
public int CHERRY_CHERRY = 5;
//The value that the user wins when he rolls a cherry/cherry/-.
public int CHERRY = 2;
//The value that the user wins when he rolls a cherry/-/-.
public void run()
{
addInitialMenu();
String instructions = readLine("Enter a Y/N here: ");
if(instructions.equals("N")){
addInstructions();
}else{
rollSlots();
}
}
public void addInitialMenu()
{
println("Do you know how to play?");
println("(Type yes or no)");
}
public void addInstructions(){
println("Instructions: ");
println(" Click to roll the slot machine. Each roll costs $1 from your wallet.");
println("Your wallet begins with $50 and it will change depending on your wins and losses.");
println("Are you ready to play?");
String instructions = readLine("Enter a Y/N here: ");
if(instructions.equals("N")){
addInstructions();
}else{
rollSlots();
}
}
public void rollSlots(){
int spins = rgen.nextInt(1, 500);
int walletMoney = 50;//Sets the initial wallet amount.
if(walletMoney > 1){//Checks to see if you have any money in your wallet.
if(spins < 20 ){//CHERRY/-/-
println("You rolled: CHERRY - -");
println("Congrats, you won $2 ");
walletMoney = walletMoney + CHERRY;
}else if(spins > 20 && spins < 50 ){//CHERRY/CHERRY/-
println("CHERRY CHERRY -");
println("Congrats, you won $5 ");
walletMoney = walletMoney + CHERRY_CHERRY;
}else if(spins > 50 && spins < 75 ){//CHERRY/CHERRY/CHERRY
println("CHERRY CHERRY CHERRY");
println("Congrats, you won $7 ");
walletMoney = walletMoney + CHERRY_CHERRY_CHERRY;
}else if(spins > 75 && spins < 110){//ORANGE/ORANGE/ORANGE
println("ORANGE ORANGE ORANGE");
println("Congrats, you won $10 ");
walletMoney = walletMoney + ORANGE_ORANGE_ORANGE;
}else if(spins > 110 && spins < 125){//PLUM/PLUM/PLUM
println("PLUM PLUM PLUM");
println("Congrats, you won $14 ");
walletMoney = walletMoney + PLUM_PLUM_PLUM;
}else if(spins > 125 && spins < 170){//BELL/BELL/BELL
println("BELL BELL BELL");
println("Congrats, you won $20 ");
walletMoney = walletMoney + BELL_BELL_BELL;
}else if(spins > 170 && spins < 200){//BAR/BAR/BAR
println("BAR BAR BAR");
println("Congrats, you won $250 ");
walletMoney = walletMoney + BAR_BAR_BAR;
}else if(spins > 200 && spins < 250){//-/-/-
println("- - -");
println("You didn't win. Better luck next time.");
}else if(spins > 250 && spins < 300){//ORANGE/CHERRY/CHERRY
println("ORANGE CHERRY CHERRY");
println("You didn't win. Better luck next time.");
}else if(spins > 300 && spins < 350){//BELL/PLUM/BELL
println("BELL PLUM BELL");
println("You didn't win. Better luck next time.");
}else{//CHERRY/CHERRY/BAR
println("CHERRY CHERRY BAR");
println("You didn't win. Better luck next time.");
}
walletMoney--;//Subtracts the fee from the users wallet.
println("Your wallet has: $" + walletMoney );
println("Do you want to roll again?");
String instructions = readLine("Enter a Y/N here: ");
if(instructions.equals("N")){
run();
}else{
rollSlots();
}
}else{
println("You have run out of money. How unfortunate.");
}
}
}
答案 0 :(得分：2)
你应该把变量放在类上。通过这种方式，它可以在任何地方访问，并且它的值将保留在rollSlots()方法的调用之间。
public class SlotMachine extends ConsoleProgram {
int walletMoney = 50;//Sets the initial wallet amount.
//...
}
答案 1 :(得分：1)
slotMachine()内的声明使其成为仅适用于该方法的局部变量。将其移至字段声明。
原因是variable scope。由于变量只在该方法中出现过，所以应用程序的其余部分并不知道;因此，无论何时调用，您都将每次创建walletMoney的新实例。
例如，您可以将其直接放在CHERRY下面。
public class SlotMachine extends ConsoleProgram {
// implementation above
public int CHERRY = 2;
//The value that the user wins when he rolls a cherry/-/-.
int walletMoney = 50;
// implementation to follow
}
答案 2 :(得分：0)
您可以将变量设置为类变量。将其设置在
之下public int CHERRY = 2;
如果这没有帮助，您可以在每次更改或程序终止后将其写入文件，并在程序启动时读取它。