Java - System.out.printf

Definition

The System.out.printf() method allows to output a formatted string. The method uses placeholders (%) in the string that are replaced by arguments.

Java syntax

System.out.printf(locale, formatString, args)

Placeholders

The placeholders have the form:

%[arg$][flags][width][.precision]conversion

The components in [square brackets] are optional.

Explanation

List of conversions

Examples

Here are some examples how to use the printf() method:

Code example

package com.learningkoala;

import java.util.Date;

public class MyFormattedOutput {

	public static void main(String[] args) {

		double x = 100000.0 / 3.0;
        // Unix timestamp (number of milliseconds since January 1, 1970)
        long exampleTime = 1711638903488L;
		Date currentDate = new Date();

		System.out.println("The default value of x is: " + x);

		// %.2f%n means format as floating point with 2 decimal places, %n is a new line
		System.out.printf("Variant 1 - The formatted value of x is: %.2f%n", x);

		// %, .2f%n - include grouping separator and format as floating point with 2
		// decimal places, %n is a new line
		System.out.printf("Variant 2 - The formatted value of x is: %, .2f%n", x);

		// %.4f%n - format as floating point with 4 decimal places, %n is a new line
		System.out.printf("Variant 3 - The formatted value of x is: %.4f%n", x);

		// %,.4f%n - include grouping separator and format as floating point with 4
		// decimal places, %n is a new line
		System.out.printf("Variant 4 - The formatted value of x is: %,.4f%n", x);

		// %,.1f%n - include grouping separator and format as floating point with 1
		// decimal place, %n is a new line
		System.out.printf("Variant 5 - The formatted value of x is: %,.1f%n", x);

		// %,.0f%n - include grouping separator and format as floating point with no
		// decimal places, %n is a new line
		System.out.printf("Variant 6 - The formatted value of x is: %,.0f%n", x);

		// %,.3f%n - include grouping separator and format as floating point with 3
		// decimal places, %n is a new line
		System.out.printf("Variant 7 - The formatted value of x is: %,.3f%n", x);

		// %2$,3.2f %1$s - positional arguments, first is a string, second is a float
		// with grouping separator and 2 decimal places
		System.out.printf("%2$,3.2f %1$s", "meters", x);

		// %tl:%tM %tp%n - format time in hours:minutes am/pm
		System.out.printf("%tl:%<tM %<tp%n", exampleTime);

		// %tB %<te%n - format date as full month name and day of month
		System.out.printf("%tB %<te%n", currentDate);

		// %tc%n - format date and time in default format (full date representation)
		System.out.printf("%tc%n", currentDate);
	}
}

Ouput:

The default value of x is: 33333.333333333336
Variant 1 - The formatted value of x is: 33333.33
Variant 2 - The formatted value of x is:  33,333.33
Variant 3 - The formatted value of x is: 33333.3333
Variant 4 - The formatted value of x is: 33,333.3333
Variant 5 - The formatted value of x is: 33,333.3
Variant 6 - The formatted value of x is: 33,333
Variant 7 - The formatted value of x is: 33,333.333
33,333.33 meters4:15 pm
January 2
Fri Jan 02 22:04:35 CET 2026

Sources: w3schools.com - Java Output printf() Method - Link