I can't get the calculations to work
I have a calculator that is suposed to figure the volume and the results come back as "0"
JButton btnCalculateVlmn = new JButton("Calculate Hot Tub Volume");
btnCalculateVlmn.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
double width = 0, length = 0, depth = 0, volume = 0;
开发者_JAVA百科 String lengthString, widthString, depthString;
lengthString = hotTubLengthText.getText();
widthString = hotTubWidthText.getText();
depthString = hotTubDepthText.getText();
try
{
if (rdbtnRoundTub.isSelected())
{
volume = Math.PI * Math.pow(length / 2.0, 2) * depth;
}
else
{
volume = Math.PI * Math.pow(length * width, 2)
* depth;
}
DecimalFormat formatter = new DecimalFormat("#,###,###.###");
hotTubVolumeText.setText("" + formatter.format(volume));
}
catch (NumberFormatException e)
{
labelTubStatus
.setText("Fill in all fields");
}
}
});
btnCalculateVlmn.setBounds(20, 200, 180, 20);
hotTubs.add(btnCalculateVlmn);
JButton Exit = new JButton("Exit");
Exit.setBounds(220, 200, 80, 20);
Exit.addActionListener(this);
hotTubs.add(Exit);
}
depth is declared as 0 and never overwritten... so the volume is always 0. I guess you should do something like:
...
double width = 0, length = 0, depth = 0, volume = 0;
String lengthString, widthString, depthString;
lengthString = hotTubLengthText.getText();
widthString = hotTubWidthText.getText();
depthString = hotTubDepthText.getText();
depth = Double.valueOf(depthString);
length = Double.valueOf(lengthString);
width = Double.valueOf(widthString);
....
You forgot to convert the strings (lengthString
, widthString
and depthString
) to doubles and assign them to your variables (length
, width
and depth
).
you have depth = 0
and
anything * 0 = 0
you forgot to convert your strings from the input fields to double.
you get 0 as result because you set length and width to 0
In both branches of your main if
condition your expressions ending * depth
. However this depth
variable seems to be set to 0 and not set to anything else. So volume will always be 0
since whatever you multiply by 0 will be 0.
Maybe you've wanted to use depthString
. Something like this:
depth = Integer.parseInt(depthString);
if (rdbtnRoundTub.isSelected())
{
volume = Math.PI * Math.pow(length / 2.0, 2) * depth;
}
else
{
volume = Math.PI * Math.pow(length * width, 2) * depth;
}
精彩评论