Java Program to Round a Number to n Decimal Places

# Java Program to Round a Number to n Decimal Places

## Example 1: Round a Number using format

``````public class Decimal {

public static void main(String[] args) {
double num = 1.34567;

System.out.format("%.4f", num);
}
}``````

When you run the program, the output will be:

`1.3457`

In the above program, we've used format() method to print the given floating point number num to 4 decimal places.  The 4 decimal places is given by the format `.4f.`

This means, print only upto 4 places after the dot (decimal places), and f means to print the floating point number.

## Example 2: Round a Number using DecimalFormat

``````import java.math.RoundingMode;
import java.text.DecimalFormat;

public class Decimal {

public static void main(String[] args) {
double num = 1.34567;
DecimalFormat df = new DecimalFormat("#.###");
df.setRoundingMode(RoundingMode.CEILING);

System.out.println(df.format(num));
}
}``````

When you run the program, the output will be:

`1.346`

In the above program, we've used `DecimalFormat` class to round a given number num.

We declare the format using the # patterns `#.###`. This means, we want num upto 3 decimal places. We also set the rounding mode to `Ceiling`, this causes the last given place to be rounded to its next number.

So, 1.34567 rounded to 3 decimal places prints 1.346, 6 is the next number for 3rd place decimal 5.