How to display an output of float data with 2 decimal places in Java?

Question

Can I do it with System.out.print? Thank you.

Answer 1

You can use DecimalFormat. One way to use it:

DecimalFormat df = new DecimalFormat();
df.setMinimumFractionDigits(2);
df.setMaximumFractionDigits(2);
System.out.println(df.format(decimalNumber));

Another one is to construct it using the #.## format.

I find all formatting options less readable than calling the formatting methods, but that's a matter of preference.

Answer 2

You can use the printf method, like so:

System.out.printf("%.2f", val);

In short, the %.2f syntax tells Java to return your variable (val) with 2 decimal places (.2) in decimal representation of a floating-point number (f) from the start of the format specifier (%).

There are other conversion characters you can use besides f:

• d: decimal integer
• o: octal integer
• e: floating-point in scientific notation

You can see some examples at Learning Java - Chapter 5

Answer 3

double d = 1.234567;
DecimalFormat df = new DecimalFormat("#.##");
System.out.print(df.format(d));

Answer 4

Look at DecimalFormat

Here is an example from the tutorial:

  DecimalFormat myFormatter = new DecimalFormat(pattern);
  String output = myFormatter.format(value);
  System.out.println(value + "  " + pattern + "  " + output);

If you choose a pattern like "###.##", you will get two decimal places, and I think that the values are rounded up. You will want to look at the link to get the exact format you want (e.g., whether you want trailing zeros)

Answer 5

Many people have mentioned DecimalFormat. But you can also use printf if you have a recent version of Java:

System.out.printf("%1.2f", 3.14159D);

See the docs on the Formatter for more information about the printf format string.