Format Specifiers in Java
Last Updated :
11 Jul, 2025
Format specifiers begin with a percent character (%) and terminate with a "type character, " which indicates the type of data (int, float, etc.) that will be converted the basic manner in which the data will be represented (decimal, hexadecimal, etc.) The general syntax of a format specifier is
% [flags] [width] [.precision] [argsize] typechar
The format() method of Formatter class accepts a wide variety of format specifiers. When an uppercase specifier is used, then letters are shown in uppercase. Otherwise, the upper- and lowercase specifiers perform the same conversion.
| Format Specifier | Conversion Applied |
|---|
| %% | Inserts a % sign |
|---|
| %x %X | Integer hexadecimal |
|---|
| %t %T | Time and Date |
|---|
| %s %S | String |
|---|
| %n | Inserts a newline character |
|---|
| %o | Octal integer |
|---|
| %f | Decimal floating-point |
|---|
| %e %E | Scientific notation |
|---|
| %g | Causes Formatter to use either %f or %e, whichever is shorter |
|---|
| %h %H | Hash code of the argument |
|---|
| %d | Decimal integer |
|---|
| %c | Character |
|---|
| %b %B | Boolean |
|---|
| %a %A | Floating-point hexadecimal |
|---|
- Space format specifier : When creating columns of numbers, it is sometimes very useful to print a space before a positive number so that positive and negative number get aligned. To do this, space format specifier can be used. Syntax:
Formatter().format("% d", -111);
Formatter().format("% d", 111);
Output:
-111
111
Example:
JAVA
// Java program to demonstrate
// the space format specifier
import java.util.*;
class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// Use Space format specifier
formatter.format("%d", -111);
System.out.println(formatter);
formatter = new Formatter();
formatter.format("% d", 111);
System.out.println(formatter);
formatter = new Formatter();
formatter.format("% d", -222);
System.out.println(formatter);
formatter = new Formatter();
formatter.format("% d", 222);
System.out.println(formatter);
}
}
- + Sign Specifier: This adds the + sign before positive numeric value, and has no effect on negative numeric value. Syntax:
Formatter().format("%+d", 111);
Output:
+111
Example:
JAVA
// Java program to demonstrate
// the + sign Specifier format specifiers.
import java.util.*;
class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// + sign specifier
formatter = new Formatter();
formatter.format("%+d", 111);
System.out.println(formatter);
// + sign specifier
// on - sign, it will have no effect
formatter = new Formatter();
formatter.format("%+d", -111);
System.out.println(formatter);
}
}
- ( specifier: This specifier puts the negative numeric values inside the parentheses, and has no effect on the positive numeric values. Syntax:
Formatter().format("%(d", -111);
Formatter().format("%(d", 111);
Output:
(111)
111
Example:
JAVA
// Java program to demonstrate
// the ( Specifiers format specifiers.
import java.util.*;
class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// ( Specifier
formatter = new Formatter();
formatter.format("%(d", -111);
System.out.println(formatter);
formatter = new Formatter();
formatter.format("%(d", 111);
System.out.println(formatter);
}
}
- Comma, Specifier: For displaying large numbers, it is often useful to add grouping separators by comma (, ). For example, the value is 1000000 more easily read when formatted as 1, 000, 000. To add grouping specifiers (, ) use the comma(, ) Specifier. Syntax:
Formatter().format("%, d", 1000000);
Output:
1, 000, 000
Example:
JAVA
// Java program to demonstrate
// the comma format specifiers.
import java.util.*;
public class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// comma Specifier
formatter = new Formatter();
formatter.format("%, d", 1000000);
System.out.println(formatter);
// comma Specifier
formatter = new Formatter();
formatter.format("%, .3f", 32659526566.4521);
System.out.println(formatter);
}
}
Output:1, 000, 000
32, 659, 526, 566.452
- Left Justification(-) Specifier: By default all output is right-shifted. That is, if the field width is longer than the data printed, data will be placed on the right side of the field. One can force output to be left-justified by placing a minus sign directly after the %. For instance, %-20.4f left justifies a floating-point number with two decimal places in a 20-character field. Syntax:
Formatter().format("|%-20.4f|", 1234.1234);
Output:
| 1234.1234|
|1234.1234 |
Example:
JAVA
// Java program to demonstrate
// the left justification format specifiers.
import java.util.*;
class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// right justify by default
formatter = new Formatter();
formatter.format("|%20.4f|", 1234.1234);
System.out.println(formatter);
// left justify
formatter = new Formatter();
formatter.format("|%-20.4f|", 1234.1234);
System.out.println(formatter);
}
}
Output:| 1234.1234|
|1234.1234 |
- The %n format specifiers: The %n format specifier is different from the others in that it doesn't take arguments. It is simply an escape sequence that inserts a character into the output. The %n inserts a newline. It can't be entered directly into the format string.
JAVA
// Java program to demonstrate
// the newline %n format specifiers.
import java.util.*;
public class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// newline format specifier
formatter.format("Geeks %nFor %nGeeks");
// Print the output
System.out.println(formatter);
}
}
- The %% format specifiers: The %% format specifier is different from the others in that it doesn't take arguments. It is simply an escape sequence that inserts a character into the output. The %% inserts a % sign. It can't be entered directly into the format string.
JAVA
// Java program to demonstrate
// the %% format specifiers.
import java.util.*;
public class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// %% format specifier
formatter.format("10 %% 4 = 2");
// Print the output
System.out.println(formatter);
}
}
- The %x %X format specifiers: The %x or %X format specifier is used to represent the integer Hexadecimal value. %x displays the hexadecimal values with lowercase alphabets whereas the %X specifier displays the hexadecimal values with uppercase alphabets.
JAVA
// Java program to demonstrate
// the integer-Hexadecimal %x and %X
// format specifiers.
import java.util.*;
public class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// %x format specifier
// It prints the number in Hexadecimal
// with lowercase alphabets
formatter.format("%x", 250);
// Print the output
System.out.println("LowerCase Hexadecimal"
+ " using %x: "
+ formatter);
// %X format specifier
// It prints the number in Hexadecimal
// with uppercase alphabets
formatter = new Formatter();
formatter.format("%X", 250);
// Print the output
System.out.println("UpperCase Hexadecimal"
+ " using %X: "
+ formatter);
}
}
Output:LowerCase Hexadecimal using %x: fa
UpperCase Hexadecimal using %X: FA
- The %e %E format specifiers: The %e or %E format specifier is used to represent the Scientific Notation of a value. %e displays the Scientific Notation with lowercase alphabets whereas the %E specifier displays the Scientific Notation with uppercase alphabets.
JAVA
// Java program to demonstrate
// the Scientific Notation %e and %E
// format specifiers.
import java.util.*;
public class GFG {
public static void main(String args[])
{
// create Formatter class object
Formatter formatter = new Formatter();
// %e format specifier
// It prints the number in Scientific Notation
// with lowercase alphabets
formatter.format("%e", 123.1234);
// Print the output
System.out.println("LowerCase Scientific Notation"
+ " using %e: "
+ formatter);
// %E format specifier
// It prints the number in Scientific Notation
// with uppercase alphabets
formatter = new Formatter();
formatter.format("%E", 123.1234);
// Print the output
System.out.println("UpperCase Scientific Notation"
+ " using %E: "
+ formatter);
}
}
Output:LowerCase Scientific Notation using %e: 1.231234e+02
UpperCase Scientific Notation using %E: 1.231234E+02
- Precision Formats A precision specifier can be applied to the %f, %e, %g, and %s format specifiers.
JAVA
// Java program to demonstrate
// Precision Format specifiers
import java.util.Formatter;
public class GFG {
public static void main(String args[])
{
// Create the Formatter instance
Formatter formatter = new Formatter();
// added floating-point data
// using the %f or %e specifiers,
// Format to 2 decimal places
// in a 16 character field.
formatter = new Formatter();
formatter.format("%16.2e", 123.1234567);
System.out.println("Scientific notation to 2 places: "
+ formatter);
// Format 4 decimal places.
formatter = new Formatter();
formatter.format("%.4f", 123.1234567);
System.out.println("Decimal floating-point"
+ " notation to 4 places: "
+ formatter);
// Format 4 places.
// The %g format specifier causes Formatter
// to use either %f or %e, whichever is shorter
formatter = new Formatter();
formatter.format("%.4g", 123.1234567);
System.out.println("Scientific or Decimal floating-point "
+ "notation to 4 places: "
+ formatter);
// Display at most 15 characters in a string.
formatter = new Formatter();
formatter.format("%.15s", "12345678901234567890");
System.out.println("String notation to 15 places: "
+ formatter);
// Format into 10 digit
formatter = new Formatter();
formatter.format("%010d", 88);
System.out.println("value in 10 digits: "
+ formatter);
}
}
Output:Scientific notation to 2 places: 1.23e+02
Decimal floating-point notation to 4 places: 123.1235
Scientific or Decimal floating-point notation to 4 places: 123.1
String notation to 15 places: 123456789012345
value in 10 digits: 0000000088
Related Article : Format Specifiers in C
Similar Reads
Basics
Introduction to JavaJava is a high-level, object-oriented programming language developed by Sun Microsystems in 1995. It is mostly used for building desktop applications, web applications, Android apps, and enterprise systems.Key Features of JavaPlatform Independent: Java is famous for its Write Once, Run Anywhere (WOR
4 min read
Java Programming BasicsJava is a class-based, object-oriented programming language that is designed to be secure and portable. Its core principle is “Write Once, Run Anywhere†(WORA), meaning Java code can run on any device or operating system that has a Java Virtual Machine (JVM).Java Development Environment: To run Java
9 min read
Java MethodsJava Methods are blocks of code that perform a specific task. A method allows us to reuse code, improving both efficiency and organization. All methods in Java must belong to a class. Methods are similar to functions and expose the behavior of objects.Example: Java program to demonstrate how to crea
7 min read
Access Modifiers in JavaIn Java, access modifiers are essential tools that define how the members of a class, like variables, methods, and even the class itself, can be accessed from other parts of our program. They are an important part of building secure and modular code when designing large applications. In this article
6 min read
Arrays in JavaIn Java, an array is an important linear data structure that allows us to store multiple values of the same type. Arrays in Java are objects, like all other objects in Java, arrays implicitly inherit from the java.lang.Object class. This allows you to invoke methods defined in Object (such as toStri
9 min read
Java StringsIn Java, a String is the type of object that can store a sequence of characters enclosed by double quotes and every character is stored in 16 bits, i.e., using UTF 16-bit encoding. A string acts the same as an array of characters. Java provides a robust and flexible API for handling strings, allowin
8 min read
Regular Expressions in JavaIn Java, Regular Expressions or Regex (in short) in Java is an API for defining String patterns that can be used for searching, manipulating, and editing a string in Java. Email validation and passwords are a few areas of strings where Regex is widely used to define the constraints. Regular Expressi
7 min read
OOPs & Interfaces
Classes and Objects in JavaIn Java, classes and objects are basic concepts of Object Oriented Programming (OOPs) that are used to represent real-world concepts and entities. A class is a template to create objects having similar properties and behavior, or in other words, we can say that a class is a blueprint for objects.An
10 min read
Java ConstructorsIn Java, constructors play an important role in object creation. A constructor is a special block of code that is called when an object is created. Its main job is to initialize the object, to set up its internal state, or to assign default values to its attributes. This process happens automaticall
10 min read
Java OOP(Object Oriented Programming) ConceptsBefore Object-Oriented Programming (OOPs), most programs used a procedural approach, where the focus was on writing step-by-step functions. This made it harder to manage and reuse code in large applications.To overcome these limitations, Object-Oriented Programming was introduced. Java is built arou
10 min read
Java PackagesPackages in Java are a mechanism that encapsulates a group of classes, sub-packages and interfaces. Packages are used for: Prevent naming conflicts by allowing classes with the same name to exist in different packages, like college.staff.cse.Employee and college.staff.ee.Employee.Make it easier to o
7 min read
Java InterfaceAn Interface in Java programming language is defined as an abstract type used to specify the behaviour of a class. An interface in Java is a blueprint of a behaviour. A Java interface contains static constants and abstract methods. Key Properties of Interface:The interface in Java is a mechanism to
11 min read
Collections
Exception Handling
Java Exception HandlingException handling in Java is an effective mechanism for managing runtime errors to ensure the application's regular flow is maintained. Some Common examples of exceptions include ClassNotFoundException, IOException, SQLException, RemoteException, etc. By handling these exceptions, Java enables deve
8 min read
Java Try Catch BlockA try-catch block in Java is a mechanism to handle exceptions. This make sure that the application continues to run even if an error occurs. The code inside the try block is executed, and if any exception occurs, it is then caught by the catch block.Example: Here, we are going to handle the Arithmet
4 min read
Java final, finally and finalizeIn Java, the keywords "final", "finally" and "finalize" have distinct roles. final enforces immutability and prevents changes to variables, methods or classes. finally ensures a block of code runs after a try-catch, regardless of exceptions. finalize is a method used for cleanup before an object is
4 min read
Chained Exceptions in JavaChained Exceptions in Java allow associating one exception with another, i.e. one exception describes the cause of another exception. For example, consider a situation in which a method throws an ArithmeticException because of an attempt to divide by zero.But the root cause of the error was an I/O f
3 min read
Null Pointer Exception in JavaA NullPointerException in Java is a RuntimeException. It occurs when a program attempts to use an object reference that has the null value. In Java, "null" is a special value that can be assigned to object references to indicate the absence of a value.Reasons for Null Pointer ExceptionA NullPointerE
5 min read
Exception Handling with Method Overriding in JavaException handling with method overriding in Java refers to the rules and behavior that apply when a subclass overrides a method from its superclass and both methods involve exceptions. It ensures that the overridden method in the subclass does not declare broader or new checked exceptions than thos
4 min read
Java Advanced
Java Multithreading TutorialThreads are the backbone of multithreading. We are living in the real world which in itself is caught on the web surrounded by lots of applications. With the advancement in technologies, we cannot achieve the speed required to run them simultaneously unless we introduce the concept of multi-tasking
15+ min read
Synchronization in JavaIn multithreading, synchronization is important to make sure multiple threads safely work on shared resources. Without synchronization, data can become inconsistent or corrupted if multiple threads access and modify shared variables at the same time. In Java, it is a mechanism that ensures that only
10 min read
File Handling in JavaIn Java, file handling means working with files like creating them, reading data, writing data or deleting them. It helps a program save and use information permanently on the computer. With the help of File Class, we can work with files. This File Class is inside the java.io package. The File class
5 min read
Java Method ReferencesIn Java, a method is a collection of statements that perform some specific task and return the result to the caller. A method reference is the shorthand syntax for a lambda expression that contains just one method call. In general, one does not have to pass arguments to method references.Why Use Met
9 min read
Java 8 Stream TutorialJava 8 introduces Stream, which is a new abstract layer, and some new additional packages in Java 8 called java.util.stream. A Stream is a sequence of components that can be processed sequentially. These packages include classes, interfaces, and enum to allow functional-style operations on the eleme
15+ min read
Java NetworkingWhen computing devices such as laptops, desktops, servers, smartphones, and tablets and an eternally-expanding arrangement of IoT gadgets such as cameras, door locks, doorbells, refrigerators, audio/visual systems, thermostats, and various sensors are sharing information and data with each other is
15+ min read
JDBC TutorialJDBC stands for Java Database Connectivity. JDBC is a Java API or tool used in Java applications to interact with the database. It is a specification from Sun Microsystems that provides APIs for Java applications to communicate with different databases. Interfaces and Classes for JDBC API comes unde
12 min read
Java Memory ManagementJava memory management is the process by which the Java Virtual Machine (JVM) automatically handles the allocation and deallocation of memory. It uses a garbage collector to reclaim memory by removing unused objects, eliminating the need for manual memory managementJVM Memory StructureJVM defines va
4 min read
Garbage Collection in JavaGarbage collection in Java is an automatic memory management process that helps Java programs run efficiently. Objects are created on the heap area. Eventually, some objects will no longer be needed.Garbage collection is an automatic process that removes unused objects from heap.Working of Garbage C
6 min read
Memory Leaks in JavaIn programming, a memory leak happens when a program keeps using memory but does not give it back when it's done. It simply means the program slowly uses more and more memory, which can make things slow and even stop working. Working of Memory Management in JavaJava has automatic garbage collection,
3 min read
Practice Java
Java Interview Questions and AnswersJava is one of the most popular programming languages in the world, known for its versatility, portability, and wide range of applications. Java is the most used language in top companies such as Uber, Airbnb, Google, Netflix, Instagram, Spotify, Amazon, and many more because of its features and per
15+ min read
Java Programs - Java Programming ExamplesIn this article, we will learn and prepare for Interviews using Java Programming Examples. From basic Java programs like the Fibonacci series, Prime numbers, Factorial numbers, and Palindrome numbers to advanced Java programs.Java is one of the most popular programming languages today because of its
8 min read
Java Exercises - Basic to Advanced Java Practice Programs with SolutionsLooking for Java exercises to test your Java skills, then explore our topic-wise Java practice exercises? Here you will get 25 plus practice problems that help to upscale your Java skills. As we know Java is one of the most popular languages because of its robust and secure nature. But, programmers
7 min read
Java Quiz | Level Up Your Java SkillsThe best way to scale up your coding skills is by practicing the exercise. And if you are a Java programmer looking to test your Java skills and knowledge? Then, this Java quiz is designed to challenge your understanding of Java programming concepts and assess your excellence in the language. In thi
1 min read
Top 50 Java Project Ideas For Beginners and Advanced [Update 2025]Java is one of the most popular and versatile programming languages, known for its reliability, security, and platform independence. Developed by James Gosling in 1982, Java is widely used across industries like big data, mobile development, finance, and e-commerce.Building Java projects is an excel
15+ min read