Formatting Floating Point Numbers
I have a variable of type double
, I need to print it in upto 3 decimals of precision but it shouldn't have any trailing zeros...
eg. I need
2.5 // not 2.500
2 // not 2.000
1.375 // exactly till 3 decimals
2.12 // not 2.120
I tried using DecimalFormatter
, Am i doing it wrong?
DecimalF开发者_JS百科ormat myFormatter = new DecimalFormat("0.000");
myFormatter.setDecimalSeparatorAlwaysShown(false);
Thanks. :)
Try the pattern "0.###"
instead of "0.000"
:
import java.text.DecimalFormat;
public class Main {
public static void main(String[] args) {
DecimalFormat df = new DecimalFormat("0.###");
double[] tests = {2.50, 2.0, 1.3751212, 2.1200};
for(double d : tests) {
System.out.println(df.format(d));
}
}
}
output:
2.5
2
1.375
2.12
Your solution is almost correct, but you should replace zeros '0' in decimal format pattern by hashes "#".
So it should look like this:
DecimalFormat myFormatter = new DecimalFormat("#.###");
And that line is not necesary (as decimalSeparatorAlwaysShown
is false
by default):
myFormatter.setDecimalSeparatorAlwaysShown(false);
Here is short summary from javadocs:
Symbol Location Localized? Meaning
0 Number Yes Digit
# Number Yes Digit, zero shows as absent
And the link to javadoc: DecimalFormat
Use NumberFormat class.
Example:
double d = 2.5; NumberFormat n = NumberFormat.getInstance(); n.setMaximumFractionDigits(3); System.out.println(n.format(d));
Output will be 2.5, not 2.500.
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