How to Round Floating point number (Double) to 2 Decimal Points in J2ME JavaME

Posted by mypapit on 08/24/07 in J2ME / JavaME, Tips, Tricks, Guide, newbie

The minimalistic design of JavaME CLDC means that a lot of packages from the standard Java has to be trimmed out and this includes the flexible NumberFormat packages which is useful for formatting numbers in Java.

The absence of NumberFormat and java.text package means that you can't even round a floating point number!

However there is a workaround to this problem, with this simple method, you can round floating point number (Double) roughly to a specific number of decimal points.

PLAIN TEXT

JAVA:

//round to 2 decimal points
double number = (double)(int)((bmi+0.005)*100.0)/100.0;
//round to 4 decimal points
double number = (double)(int)((bmi+0.00005)*10000.0)/10000.0;

The code above shows you how to round a double to 2 and 4 decimal points, you can change the number of zeros above to round it to your desired decimal points.

Hope that will help you in your JavaME / J2ME programming.

Tags: j2me, javame, midp, java, sdk, j2se