The printf(String, Object) method of PrintWriter Class in Java is used to print a formatted string in the stream. The string is formatted using specified format and arguments passed as the parameter.
Syntax:
public PrintWriter printf(String format, Object…args)
Parameters: This method accepts two mandatory parameter:
- format which is the format according to which the String is to be formatted.
- args which is the number of arguments for the formatted string. It can be optional, i.e. no arguments or any number of arguments according to the format.
Return Value: This method returns this PrintWriter instance.
Exception: This method throws following exceptions:
- NullPointerException This is thrown if the format is null.
- IllegalFormatException This is thrown if the format specified is illegal or there are insufficient arguments.
Below methods illustrates the working of printf(String, Object) method:
Program 1:
// Java program to demonstrate// PrintWriter printf(String, Object) method  import java.io.*;  class GFG {    public static void main(String[] args)    {          try {              // Get the parameters            double arg = 47.65734;              String format = "GeeksForGeeks %.8f";              // Create a PrintWriter instance            PrintWriter writer                = new PrintWriter(System.out);              // print the formatted string            // to this writer using printf() method            writer.printf(format, arg);              writer.flush();        }        catch (Exception e) {            System.out.println(e);        }    }} |
Output:
GeeksForGeeks 47.65734000
Program 2:
// Java program to demonstrate// PrintWriter printf(String, Object) method  import java.io.*;  class GFG {    public static void main(String[] args)    {          try {              // Get the parameters              String arg1 = "GFG";            String arg2 = "Lazyroar";              String format = "A Computer Science "                            + "Portal %1$s, %1$s and %2$s";              // Create a PrintWriter instance            PrintWriter writer                = new PrintWriter(System.out);              // print the formatted string            // to this writer using printf() method            writer.printf(format, arg1, arg2);              writer.flush();        }        catch (Exception e) {            System.out.println(e);        }    }} |
Output:
A Computer Science Portal GFG, GFG and Lazyroar
