双变量的 Java 错误

Question

我正在尝试向程序添加交互式输入。我已经研究了几个小时但无法弄清楚。这是代码 -

// This program calculates an employee's take home pay. 
    public class Payrolls
        import javax.swing.JOptionPane;

    {
        public static void main(String args[])
        {
            String salaryString;
            double salary;
            double stateTax;
            double federalTax;
            String numDependentsString;
            double numDependents;
            double dependentDeduction;
            double totalWithholding;
            double takeHomePay;

            salaryString = JOptionPane.showInputDialog ("Enter Salary Here: ");
            salary = double.parseDouble (salaryString);
            numDependentsString = JOptionPane.showInputDialog     ("Enter Number of Dependents: ");
            numDependents = double.parseDouble (numDependentsString);

            // Calculate state tax here.
            stateTax = salary * .06;

            System.out.println("State Tax: $" + stateTax);
            // Calculate federal tax here. 
            federalTax = salary * .25;

            System.out.println("Federal Tax: $" + federalTax);
            // Calculate dependant deduction here.
            dependentDeduction = (salary * .02) * numDependents;

            System.out.println("Dependents: $" + dependentDeduction);
            // Calculate total withholding here.
            totalWithholding = stateTax + federalTax;

            // Calculate take home pay here.
            takeHomePay = salary - totalWithholding + dependentDeduction;

            System.out.println("Salary: $" + salary);
            System.out.println("Take Home Pay: $" + takeHomePay);
            System.exit(0);
        }
    }

我有 9 个错误 -

Payrolls.java:19: error: class expected
                salary = double.parseDouble (salaryString);
                                ^
Payrolls.java:19: error: ';' expected
                salary = double.parseDouble (salaryString);
                                           ^
Payrolls.java:19: error: not a statement
                salary = double.parseDouble (salaryString);
                                             ^
Payrolls.java:19: error: ';' expected
                salary = double.parseDouble (salaryString);
                                                         ^
Payrolls.java:21: error: class expected
                numDependents = double.parseDouble (numDependentsString);
                                       ^
Payrolls.java:21: error: ';' expected
                numDependents = double.parseDouble (numDependentsString);
                                                  ^
Payrolls.java:21: error: not a statement
                numDependents = double.parseDouble (numDependentsString);
                                                    ^
Payrolls.java:21: error: ';' expected
                numDependents = double.parseDouble (numDependentsString);

Answer 1

Double.parseDouble (salaryString);

它是Double.parseDouble，而不是double.parseDouble。 :)

parseDouble 方法来自Double类(class)。