Java DecimalFormat rounding down

Question

I am using DecimalFormatter to read in formatted decimal string values and convert them to float. However, when I run:

    DecimalFormat formatter = new DecimalFormat("####,####.00");
    String floatStr = "177,687.71";
    float val1 = formatter.parse(floatStr).floatValue();
    System.out.println(val1);

...I get 177678.7 instead of 177678.71. Why is this? How do I avoid rounding the hundredths place?

Thanks!

Answer 1

You appear to need more precision than a float to represent that number.

Taking the formatter out of the picture:

Float.parseFloat("177687.71");
177687.7 // Ouch

Double.parseDouble("177687.71");
177687.71 // Ok

It seems that you'll need to use a double instead.

If this is for representing money though as @Dawood is suggesting , then yes, do not use floating types to represent money, since they are estimations and will accumulate errors over time. A format like BigDecimal would be more appropriate, or even just storing an integer representing cents. Money is not something that you want to subject to rounding errors.