Android将double乘以int [java]

Question

I have a double value a = 0.00059 and an Integer value which gets incremented and multiplied with the double value (say b = 1)

when I set the answer to the textview

//for b = 1
view.setText(((double)(a*b)));

the answer I get is " 5.9E-4 " however it should be 0.00059.

am I multiplying the values correctly.?

Answer 1

In addition to the other answers provided, you can use a formatter:

NumberFormat formatter = new DecimalFormat("#.#####");
view.setText(formatter.format(a*b));

Answer 2

You are multiplying them correctly. The values 5.9E-4 and 0.00059 are equivalent, mathematically and programmatically. The representation 5.9E-4 is like scientific notation, ie 5.9x10^(-4) is equivalent to 0.00059.

Answer 3

You get the same value as you want to get, but formatted in a scientific notation. What you need to do is to explicitly convert it to String:

view.setText(String.format("%f", a*b));

And you could eventually specify the number of decimal places to print after the decimal separator in this way:

// displays two digits after the decimal separator
view.setText(String.format("%.2f", a*b));