java - 根据婚姻状况寻找税收收入

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How do I compare strings in Java?

（23个答案）


在10个月前关闭。





我正在做这个Java作业，使用if else语句和joptionpane根据婚姻状况查找税收收入。问题是在获得税收和婚姻状况输入后，输出不会显示出来，只是终止了程序。也没有错误。

我尝试将分号放在第一个if语句之后，并且以某种方式起作用，但是它显示了2种不同的输出，而不是1种

public class Program_4_2 {

public static void main (String[] args) {

String status;
String tax;
double tax_income;

status = JOptionPane.showInputDialog("Please enter s for single, m for married: ");
tax = JOptionPane.showInputDialog("Enter Your Tax Income: ");
tax_income = Double.parseDouble(tax);

// SINGLE TAX;
if (status == "s")
{
    if (tax_income > 0 && tax_income < 8000)
        {
        tax_income = tax_income * 0.1 + 0;
        JOptionPane.showMessageDialog(null, "Your Tax is " + tax_income);
        }

    else if (tax_income > 8000 && tax_income < 32000)
        {
            tax_income = (tax_income - 8000) * 0.15 + 800;
            JOptionPane.showMessageDialog(null, "Your Tax is " + tax_income);
        }
    else if (tax_income > 32000)
        {
            tax_income = (tax_income - 32000) * 0.25 + 4400;
            JOptionPane.showMessageDialog(null, "Your Tax is " + tax_income);
        }
}

// Married Tax
if (status == "m")
{
    if (tax_income > 0 && tax_income < 16000)
        {
            tax_income = tax_income * 0.1 + 0;
            JOptionPane.showMessageDialog(null, "Your Tax is " + tax_income);
        }

    else if (tax_income > 16000 && tax_income < 64000)
        {
            tax_income = (tax_income - 16000) * 0.15 + 1600;
            JOptionPane.showMessageDialog(null, "Your Tax is " + tax_income);
        }
    else if (tax_income > 64000)
        {
            tax_income = (tax_income - 64000) * 0.25 + 8800;
            JOptionPane.showMessageDialog(null, "Your Tax is " + tax_income);
        }
}

}
}

示例输出为：


用户输入状态->“ s”->用户然后输入税款->“ 9000”->输出应显示->“ 950”或“ 900”（如果状态输入为m

最佳答案

看来您可以使用它，但为了将来参考，请不要使用==来比较Strings。

比较字符串的正确方法是使用.equals，如下所示：

status.equals("m")