In this example we shall show you how to format a number with a custom NumberFormat. NumberFormat provides the interface for formatting and parsing numbers. It also provides methods for determining which locales have number formats, and what their names are. To format a number with custom NumberFormat one should perform the following steps:
- Create a new DecimalFormat, using a String pattern. The pattern can consist of zeros, which will set a digit or 0 if no digit present, a #, which will set a digit or nothing if no digit present. We can use the decimal point in the pattern, or the comma, to group numbers. We can also use ‘, in order to quote literal symbols or text.
- Invoke the
format(double number)API method of the DecimalFormat, using a double number as parameter in order to create the formatted String value,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
import java.text.DecimalFormat;
import java.text.NumberFormat;
public class FormatNumberWithCustomNumberFormat {
public static void main(String[] args) {
NumberFormat formatter;
String number;
// 0 --> a digit or 0 if no digit present
formatter = new DecimalFormat("00000");
number = formatter.format(-1234.567);
System.out.println("Number 1: " + number);
formatter = new DecimalFormat("0000.000");
number = formatter.format(-1234.567);
System.out.println("Number 2: " + number);
// # --> a digit or nothing if no digit present
formatter = new DecimalFormat("##");
number = formatter.format(-1234.567);
System.out.println("Number 3: " + number);
formatter = new DecimalFormat("##00");
number = formatter.format(0);
System.out.println("Number 4: " + number);
// . --> the decimal point
formatter = new DecimalFormat(".00");
number = formatter.format(-0.123);
System.out.println("Number 5: " + number);
formatter = new DecimalFormat("0.00");
number = formatter.format(-0.123);
System.out.println("Number 6: " + number);
formatter = new DecimalFormat("#.#");
number = formatter.format(-1234.567);
System.out.println("Number 7: " + number);
formatter = new DecimalFormat("#.######");
number = formatter.format(-1234.567);
System.out.println("Number 8: " + number);
formatter = new DecimalFormat(".######");
number = formatter.format(-1234.567);
System.out.println("Number 9: " + number);
formatter = new DecimalFormat("#.000000");
number = formatter.format(-1234.567);
System.out.println("Number 10: " + number);
// , --> used to group numbers
formatter = new DecimalFormat("#,###,###");
number = formatter.format(-1234.567);
System.out.println("Number 11: " + number);
number = formatter.format(-1234567.890);
System.out.println("Number 12: " + number);
// '--> used to quote literal symbols
formatter = new DecimalFormat("'#'#");
number = formatter.format(-1234.567);
System.out.println("Number 13: " + number);
formatter = new DecimalFormat("'text'#");
number = formatter.format(-1234.567);
System.out.println("Number 14: " + number);
}
}
Output:
Number 1: -01235
Number 2: -1234.567
Number 3: -1235
Number 4: 00
Number 5: -.12
Number 6: -0.12
Number 7: -1234.6
Number 8: -1234.567
Number 9: -1234.567
Number 10: -1234.567000
Number 11: -1,235
Number 12: -1,234,568
Number 13: -#1235
Number 14: -text1235
This was an example of how to format a number with custom NumberFormat in Java.
