Not displaying decimals if double is a whole number?

Question

I am making a graphical calculator program in Java and have a method that performs an operation based on user input, and returns a double to be displayed in a JTextField. However, I would like the result to be displayed as a whole number, without a following ".0" where there are no significant digits after the decimal point, but still display decimal points when necessary. What's the most efficient way of doing this?

Answer 1

You can use DecimalFormat for suppressing the trailing characters, e.g.:

DecimalFormat format = new DecimalFormat("#.##");
double doubleFromTextField = Double.parseDouble(myField.getText());
System.out.println(format.format(doubleFromTextField));