我不知道为什么我无法使用 if 和 else if 语句正确地编写我的简单计算代码。
所有变量都只返回一个“0.0”值，我猜不出哪里出了问题？你能帮我解决这个问题吗？
这是我的代码:
public class MonthlyComputation extends MyActivity
{
String civil_status;
public void DoComputation()
{
final EditText net_salary = (EditText) findViewById(R.id.et_net_monthly);
final EditText tax_due = (EditText) findViewById(R.id.et_taxdue);
final Button btn_compute = (Button) findViewById(R.id.btn_compute_from_monthly);
final TextView txt3 = (TextView) findViewById(R.id.textView3);
final TextView txt4 = (TextView) findViewById(R.id.textView4);
final TextView txt5 = (TextView) findViewById(R.id.textView5);
final TextView txt6 = (TextView) findViewById(R.id.textView6);
btn_compute.setOnClickListener(new Button.OnClickListener()
{
@Override
public void onClick(View v)
{
double netSalary, taxDue, rate = 0, exemption = 0, subtrahend = 0, withRate;
String ns, td, r, e, s, wr;
ns = net_salary.getText().toString();
netSalary = Double.parseDouble(ns);
/* Single or Married with no dependent */
if ((civil_status == "SME") && (netSalary >= 4167) && (netSalary < 5000))
{
rate = 0.05;
exemption = 0.00;
subtrahend = 4167;
}
else if ((civil_status == "SME") && (netSalary >= 5000) && (netSalary < 6667))
{
rate = 0.1;
exemption = 41.67;
subtrahend = 5000;
}
taxDue = netSalary - subtrahend;
withRate = taxDue * rate;
taxDue = withRate + exemption;
tax_due.setText(Double.toString(taxDue));
td = String.valueOf(taxDue);
e = String.valueOf(exemption);
s = String.valueOf(subtrahend);
r = String.valueOf(rate);
txt3.setText(td);
txt4.setText(e);
txt5.setText(s);
txt6.setText(r);
}
});
}
最佳答案
永远不会使用==来比较String(和一般的对象)，你很可能会得到false 因为它比较对象引用，而不是值。
有关更多信息，请参阅其他问题:Java String.equals versus ==
解决方案？使用 .equals() 代替:
...
if ("SME".equals(civil_status) && (netSalary >= 4167) && (netSalary < 5000))
{
rate = 0.05;
exemption = 0.00;
subtrahend = 4167;
}
...
关于java - 使用 IF、ELSE IF 语句计算，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13670921/