我正在使用JOptionPane在java中编写基本的计算器程序。我对此非常陌生，到目前为止我得到的所有帮助都非常感谢！
我的程序假设要求用户输入一个号码，而不是让他们选择要使用的运算符（+， - ，*，/，％），而不是要求用户输入第二个号码。完成所有这些后，将执行计算并显示结果。
我有工作代码循环计算器，以便在计算完成后，系统会询问用户是否要再次使用它。我的代码有效，但我想调整的是，当用户被问及是否要继续并且他们说是，而不是循环返回并让输入框说“欢迎来到计算器！\ n请输入您的第一个号码：“）我希望它只能说”请输入您的第一个号码：“而不是继续（因为用户不需要再次欢迎）。
public static void main(String[] args) {
double numOne; //first number as Float
double numTwo; //second number as Float
double result; //result of equation
String num1; //first number as String
String num2; //second number as String
String input; //operator type (+,-,*,/,%)
boolean useCalculator = false; //False to quit, True to use
while (!useCalculator) {
num1 = JOptionPane.showInputDialog(null, "Welcome to the calculator!\nPlease enter your first number:");
numOne = Double.parseDouble(num1);
input = JOptionPane.showInputDialog(null, "Thank you! What would you like to do?\nPlease choose from the following options:\n+\n-\n*\n%\n/");
while (input == null || !(input.equals("+") || input.equals("*") || input.equals("/") || input.equals("-"))) {
input = JOptionPane.showInputDialog(null, "The operator is invalid. Please select a correct operator.\nPlease choose from the following options:\n+\n-\n*\n%\n/");
}
num2 = JOptionPane.showInputDialog(null, "Thank you!\nPlease enter your second number:");
numTwo = Double.parseDouble(num2);
}
}
和
public static boolean askYesNoQuestion(String prompt) {
String confirmationInput;
boolean repeat = false; //false to quite calc, true to repeat use of calc
while (true) {
confirmationInput = JOptionPane.showInputDialog(null,
prompt + " (Please answer yes or no)");
if (confirmationInput.equalsIgnoreCase("y") || confirmationInput.equalsIgnoreCase("yes")) {
prompt = "Please enter your first number";
return true;
} else if (confirmationInput.equalsIgnoreCase("n") || confirmationInput.equalsIgnoreCase("no")) {
JOptionPane.showMessageDialog(null, "You have decided to quit the calculator program.\n Goodbye!");
return false;
}
if (!repeat) {
prompt = "That is an invalid choice. " + prompt;
repeat = true;
}
}
}
与我的其他问题相同，我想了解并学习如何做到这一点。为了清晰起见，我添加了部分代码（如果需要，我可以添加整个代码）但我真正想要的是如何实现这一点的解释，以便我可以自己尝试并通过它来完成。如果这是广泛的，我道歉，如果需要，我很乐意清除任何事情！ ：）
@ajb 大家好 - 我已经尝试删除一些更改（添加另一个while循环并删除提示）但我收到了返回错误。我试图查看这个，我发现它与使用void的main方法有关，但我不确定如何解决这个问题。如果有人对下面的新代码有任何进一步的提示（所以我可以再次尝试并完成它），我真的很感激！
import javax.swing.JOptionPane;
public class test {
public static void main(String[] args) {
double numOne; //first number as Float
double numTwo; //second number as Float
double result; //result of equation
String num1; //first number as String
String num2; //second number as String
String input; //operator type (+,-,*,/,%)
String confirmationInput;
boolean useAgain = false;
boolean useCalculator = false; //false if user decides to quit, true if user continues to use calculator
while (!useCalculator) {
num1 = JOptionPane.showInputDialog(null, "Welcome to the calculator!\nPlease enter your first number:");
numOne = Double.parseDouble(num1);
input = JOptionPane.showInputDialog(null, "Thank you! What would you like to do?\nPlease choose from the following options:\n+\n-\n*\n%\n/");
//while loop gathers user input. Asks user repeatedly until a valid operator is entered
while (input == null || !(input.equals("+") || input.equals("*") || input.equals("/") || input.equals("-") || input.equals("%"))) {
input = JOptionPane.showInputDialog(null, "The operator " + input + " is invalid. Please select a correct operator.\nPlease choose from the following options:\n+\n-\n*\n%\n/");
}
num2 = JOptionPane.showInputDialog(null, "Thank you!\nPlease enter your second number:");
numTwo = Double.parseDouble(num2);
//calculates result of user input based on operator choosen
if (input != null && input.equals("+")) {
add(numOne, numTwo);
result = add(numOne, numTwo);
JOptionPane.showMessageDialog(null, "The result of " + numOne + " " + input + " " + numTwo + " is: " + result);
} else if (input != null && input.equals("-")) {
minus(numOne, numTwo);
result = minus(numOne, numTwo);
JOptionPane.showMessageDialog(null, "The result of " + numOne + " " + input + " " + numTwo + " is: " + result);
} else if (input != null && input.equals("*")) {
multiply(numOne, numTwo);
result = multiply(numOne, numTwo);
JOptionPane.showMessageDialog(null, "The result of " + numOne + " " + input + " " + numTwo + " is: " + result);
} else if (input != null && input.equals("/")) {
divide(numOne, numTwo);
result = divide(numOne, numTwo);
JOptionPane.showMessageDialog(null, "The result of " + numOne + " " + input + " " + numTwo + " is: " + result);
} else if (input != null && input.equals("%")) {
modul(numOne, numTwo);
result = modul(numOne, numTwo);
JOptionPane.showMessageDialog(null, "The result of " + numOne + " " + input + " " + numTwo + " is: " + result);
}
if (!useCalculator) {
JOptionPane.showInputDialog(null, "Would you like to continue using this calculator? (Please answer yes or no)");
while (true) {
if (confirmationInput.equalsIgnoreCase("y") || confirmationInput.equalsIgnoreCase("yes")) {
num1 = JOptionPane.showInputDialog(null, "Please enter your first number:");
return true;
} else if (confirmationInput.equalsIgnoreCase("n") || confirmationInput.equalsIgnoreCase("no")) {
JOptionPane.showMessageDialog(null, "You have decided to quit the calculator program.\n Goodbye!");
return false;
}
if (!useAgain) {
JOptionPane.showInputDialog(null, "That is an invalid choice.\nWould you like to continue using this calculator? (Please answer yes or no)");
useAgain = true;
}
}
}
System.out.println("End of calculator program. Program completed successfully");
}
}