What's the right way to parseFloat in Java

Question

I notice some issues with the Java float precision

       Float.parseFloat(\"0.0065\") - 0.001  // 0.0055000000134110451
       new Float(\"0.027\") - 0.001          


        

Answer 1

You're getting the right results. There is no such float as 0.027 exactly, nor is there such a double. You will always get these errors if you use float or double.

float and double are stored as binary fractions: something like 1/2 + 1/4 + 1/16... You can't get all decimal values to be stored exactly as finite-precision binary fractions. It's just not mathematically possible.

The only alternative is to use BigDecimal, which you can use to get exact decimal values.