Formatted Output in Java using printf()
Last Updated :
12 Jan, 2024
Sometimes in programming, it is essential to print the output in a given specified format. Most users are familiar with the printf function in C. Let us discuss how we can Formatting Output with printf() in Java in this article.
Formatting Using Java Printf()
printf() uses format specifiers for formatting. There are certain data types are mentioned below:
- For Number Formatting
- Formatting Decimal Numbers
- For Boolean Formatting
- For String Formatting
- For Char Formatting
- For Date and Time Formatting
i). For Number Formatting
The number itself includes Integer, Long, etc. The formatting Specifier used is %d.
Below is the implementation of the above method:
Java
import java.io.*;
class GFG {
public static void main (String[] args) {
int a=10000;
System.out.printf("%,d%n",a);
}
}
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ii). For Decimal Number Formatting
Decimal Number Formatting can be done using print() and format specifier %f .
Below is the implementation of the above method:
Java
import java.io.*;
class GFG {
public static void main(String[] args)
{
double a = 3.14159265359;
System.out.printf("%f\n", a);
System.out.printf("%5.3f\n", a);
System.out.printf("%5.2f\n", a);
}
}
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Output
3.141593
3.142
3.14
iii). For Boolean Formatting
Boolean Formatting can be done using printf and ( ‘%b’ or ‘%B’ ) depending upon the result needed.
Below is the implementation of the above method:
Java
import java.io.*;
class GFG {
public static void main(String[] args)
{
int a = 10;
Boolean b = true, c = false;
Integer d = null;
System.out.printf("%b\n", a);
System.out.printf("%B\n", b);
System.out.printf("%b\n", c);
System.out.printf("%B\n", d);
}
}
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Output
true
TRUE
false
FALSE
iv). For Char Formatting
Char Formatting is easy to understand as it need printf() and Charracter format specifier used are ‘%c’ and ‘%C’.
Below is the implementation of the above method:
Java
import java.io.*;
class GFG {
public static void main(String[] args)
{
char c = 'g';
System.out.printf("%c\n", c);
System.out.printf("%C\n", c);
}
}
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v). For String Formatting
String Formatting requires the knowledge of Strings and format specifier used ‘%s’ and ‘%S’.
Below is the implementation of the above method:
Java
import java.io.*;
class GFG {
public static void main(String[] args)
{
String str = "geeksforgeeks";
System.out.printf("%s \n", str);
System.out.printf("%S \n", str);
str = "GFG";
System.out.printf("%S \n", str);
System.out.printf("%s \n", str);
}
}
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Output
geeksforgeeks
GEEKSFORGEEKS
GFG
GFG
vi). For Date and Time Formatting
Formatting of Date and Time is not as easy as the data-type used above. It uses more than simple format specifier knowledge can be observed in the example mentioned below.
Below is the implementation of the above method:
Java
import java.io.*;
import java.util.*;
class GFG {
public static void main(String[] args)
{
Date time = new Date();
System.out.printf("Current Time: %tT\n", time);
System.out.printf("Hours: %tH Minutes: %tM Seconds: %tS\n",
time,time, time);
System.out.printf("%1$tH:%1$tM:%1$tS %1$tp %1$tL %1$tN %1$tz %n",
time);
}
}
|
Output
Current Time: 11:32:36
Hours: 11 Minutes: 32 Seconds: 36
11:32:36 am 198 198000000 +0000
Note: System.out.format() is equivalent to printf() and can also be used.
Other Methods for Formatting
1. Formatting using DecimalFormat class
DecimalFormat is used to format decimal numbers.
Below is the implementation of the above method:
Java
import java.text.DecimalFormat;
class JavaFormatter2 {
public static void main(String args[])
{
double num = 123.4567;
DecimalFormat ft = new DecimalFormat("####");
System.out.println("Without fraction part: num = "
+ ft.format(num));
ft = new DecimalFormat("#.##");
System.out.println("Formatted to Give precision: num = "
+ ft.format(num));
ft = new DecimalFormat("#.000000");
System.out.println("appended zeroes to right: num = "
+ ft.format(num));
ft = new DecimalFormat("00000.00");
System.out.println("formatting Numeric part : num = "
+ ft.format(num));
double income = 23456.789;
ft = new DecimalFormat("$###,###.##");
System.out.println("your Formatted Dream Income : "
+ ft.format(income));
}
}
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Output
Without fraction part: num = 123
Formatted to Give precision: num = 123.46
appended zeroes to right: num = 123.456700
formatting Numeric part : num = 00123.46
your Formatted Dream Income : $23,456.79
2. Formatting dates and parsing using SimpleDateFormat class
This class is present in java.text package.
Below is the implementation of the above method:
Java
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
class Formatter3 {
public static void main(String args[])
throws ParseException
{
SimpleDateFormat ft
= new SimpleDateFormat("dd-MM-yyyy");
String str = ft.format(new Date());
System.out.println("Formatted Date : " + str);
str = "02/18/1995";
ft = new SimpleDateFormat("MM/dd/yyyy");
Date date = ft.parse(str);
System.out.println("Parsed Date : " + date);
}
}
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Output
Formatted Date : 24-01-2022
Parsed Date : Sat Feb 18 00:00:00 UTC 1995
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