Format floating point number with leading zeros [duplicate]

问题

This question already has answers here:

printf how to do floating points with leading zeros (3 answers)

Closed 4 years ago.

Why does

System.out.format("%03.3f", 1.23456789);

print 1.235 instead of 001.235?

How has my format string to look like to get 001.235 as output of the following code line?

System.out.format(format, 1.23456789);

回答1:

Number after %0 here defines full width including decimal point, so you need to change it to 7:

System.out.format("%07.3f", 1.23456789);

回答2:

DecimalFormat formatter = (DecimalFormat)NumberFormat.getNumberInstance(Locale.US);
formatter.applyPattern("000.###");
System.out.format(formatter.format(1.23456789));

Result:

001.234

Demo

来源：https://stackoverflow.com/questions/30081930/format-floating-point-number-with-leading-zeros