Console format(String, Object) method in Java with Examples

The format(String, Object) method of Console class in Java is used to write a formatted string to the output stream of the console. It uses the specified format string and arguments.

Syntax:

public Console format(String fmt,
                      Object... args)

Parameters: This method accepts two parameters:

• fmt – It represents the format of the string.
• args – It represents the arguments that are referenced by the format specifiers in the string format.

Return value: This method returns the console.

Exceptions: This method throws IllegalFormatException if string format contains an illegal syntax or a format specifier is not compatible with the given arguments or insufficient arguments given the format string or other conditions that are illegal.

Note: System.console() returns null in an online IDE.

Below programs illustrate format(String, Object) method in Console class in IO package:

Program 1:

// Java program to illustrate
// Console format(String, Object) method

import java.io.*;

public class GFG {
    public static void main(String[] args)
    {
        // Create the console object
        Console cnsl
            = System.console();

        if (cnsl == null) {
            System.out.println(
                "No console available");
            return;
        }

        String fmt = "%1$4s %2$10s %3$10s%n";

        cnsl.format(fmt, "Books", "Author", "Price");
        cnsl.format(fmt, "-----", "------", "-----");
        cnsl.format(fmt, "DBMS", "Navathe", "800");
        cnsl.format(fmt, "Algorithm", "Cormen", "925");
        cnsl.format(fmt, "Operating System", "Rajib Mall", "750");
    }
}

Output:

Program 2:

// Java program to illustrate
// Console format(String, Object) method

import java.io.*;

public class GFG {
    public static void main(String[] args)
    {
        // Create the console object
        Console cnsl
            = System.console();

        if (cnsl == null) {
            System.out.println(
                "No console available");
            return;
        }

        String fmt = "%1$4s %2$10s %3$10s%n";

        cnsl.format(fmt, "Items", "Quantity", "Price");
        cnsl.format(fmt, "-----", "------", "-----");
        cnsl.format(fmt, "Tomato", "1 Kg", "80");
        cnsl.format(fmt, "Apple", "3 Kg", "500");
        cnsl.format(fmt, "Potato", "2 Kg", "75");
    }
}

Output:

References:
https://docs.oracle.com/javase/10/docs/api/java/io/Console.html#format(java.lang.String, java.lang.Object…)