MessageFormat format() method in Java with Example : Set – 2

The format() method of java.text.MessageFormat class is used to get the formatted array of object according to the specified pattern of message format object. new string pattern will be considered while performing the action.
Syntax:

public static String format(String pattern,
                            Object... arguments)

Parameter: This method takes following argument as a parameter. 

• pattern :– string pattern according to which array of object will be formatted
• arguments :- array of object over which formatting is going to take place.

Return Value: This method returns string value which will have the formatted array of object in string format.
Exception: This method throws NullPointerException if pattern is null.
Below are the examples to illustrate the format() method:
Example 1:

Java

// Java program to demonstrate
// format() method

import java.text.*;
import java.util.*;
import java.io.*;

public class GFG {
    public static void main(String[] argv)
    {
        try {
            // creating and initializing new MessageFormat Object
            MessageFormat mf
                = new MessageFormat("{0, number, #}, {0, number, #.##}, {0, number}");

            // Creating and initializing an array of type Double
            // to be formatted
            Object[] objs = { new Double(4.234567) };

            // Formatting an array of object
            // using format() method
            String str = mf.format("{0, number, #.#}", objs);

            // display the result
            System.out.println("formatted array : "
                               + str);
        }
        catch (NullPointerException e) {
            System.out.println("pattern is null " + e);
            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

formatted array : 4.2

Example 2:

Java

// Java program to demonstrate
// format() method

import java.text.*;
import java.util.*;
import java.io.*;

public class GFG {
    public static void main(String[] argv)
    {
        try {
            // creating and initializing new MessageFormat Object
            MessageFormat mf
                = new MessageFormat("{0, number, #}, {0, number, #.##}, {0, number}");

            // Creating and initializing an array of type Double
            // to be formatted
            Object[] objs = { new Double(4.234567) };

            // Formatting an array of object
            // using format() method
            String str = mf.format(null, objs);

            // display the result
            System.out.println("formatted array : "
                               + str);
        }
        catch (NullPointerException e) {
            System.out.println("pattern is null ");
            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

pattern is null 
Exception thrown : java.lang.NullPointerException

Reference: https://docs.oracle.com/javase/9/docs/api/java/text/MessageFormat.html#format-java.lang.String-java.lang.Object…-