Does Java have Printf?

In this short post, we will discuss about printf() method in Java. The method is part of the java.io.PrintStream class and provides String formatting similar to the printf() function in C.

Java printf() Method

The printf() method is not only there in C, but also in Java.

The printf() method present in the PrintStream class.

It’s used to print formatted strings using various format specifiers.

PrintStream printf() Methods

There are two overloaded printf() methods in PrintStrem class:

• PrintStream printf​(String format, Object... args) - A convenience method to write a formatted string to this output stream using the specified format string and arguments.
• PrintStream printf​(Locale l, String format, Object... args) - A convenience method to write a formatted string to this output stream using the specified format string and arguments.

Format Specifiers

Let’s look at the available format specifiers available for print:

%c - character
%d - decimal (integer) number (base 10)
%e - exponential floating-point number
%f - floating-point number
%i - integer (base 10)
%o - octal number (base 8)
%s - String
%u - unsigned decimal (integer) number
%x - number in hexadecimal (base 16)
%t - formats date/time
%% - print a percent sign
\% - print a percent sign
Note: %n or \n are used as line separators in print().

Escape Characters

Following are the escape characters available in printf():

\b - backspace
\f - next line first character starts to the right of current line last character
\n - newline
\r - carriage return
\t - tab
\\ - backslash

Java printf() Example

The below example the usage of printf() method and String, Char, Boolean, Number, Float formatting:

import java.util.Date;
import java.util.Locale;

public class PrintfExamples {

    public static void main(String[] args) {

        printfNewLine();
        printfChar();
        printfString();
        printfNumber();
        printfDateTime();
        printfBoolean();
    }

    private static void printfNewLine() {
        System.out.printf("sourcecodeexamples%nline%nterminator");
    }

    private static void printfString() {
        System.out.printf("'%s' %n", "sourcecodeexamples");
        System.out.printf("'%S' %n", "sourcecodeexamples");
        System.out.printf("'%15s' %n", "sourcecodeexamples");
        System.out.printf("'%-10s' %n", "sourcecodeexamples");
    }

    private static void printfChar() {
        System.out.printf("%c%n", 's');
        System.out.printf("%C%n", 's');
    }

    private static void printfNumber() {
        System.out.printf("simple integer: %d%n", 10000L);

        System.out.printf(Locale.US, "%,d %n", 10000);
        System.out.printf(Locale.ITALY, "%,d %n", 10000);

        System.out.printf("%f%n", 5.1473);
        System.out.printf("'%5.2f'%n", 5.1473);
        System.out.printf("'%5.2e'%n", 5.1473);
    }

    private static void printfBoolean() {
        System.out.printf("%b%n", null);
        System.out.printf("%B%n", false);
        System.out.printf("%B%n", 5.3);
        System.out.printf("%b%n", "random text");
    }

    private static void printfDateTime() {
        Date date = new Date();
        System.out.printf("%tT%n", date);
        System.out.printf("hours %tH: minutes %tM: seconds %tS%n", date, date, date);
        System.out.printf("%1$tH:%1$tM:%1$tS %1$tp %1$tL %1$tN %1$tz %n", date);

        System.out.printf("%1$tA %1$tB %1$tY %n", date);
        System.out.printf("%1$td.%1$tm.%1$ty %n", date);
    }
}

Output

sourcecodeexamples
line
terminators
S
'sourcecodeexamples' 
'SOURCECODEEXAMPLES' 
'sourcecodeexamples' 
'sourcecodeexamples' 
simple integer: 10000
10,000 
10.000 
5.147300
' 5.15'
'5.15e+00'
14:22:53
hours 14: minutes 22: seconds 53
14:22:53 pm 391 391000000 +0000 
Friday February 2021 
19.02.21 
false
FALSE
TRUE
true

References

https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/io/PrintStream.html