The setFormatByArgumentIndex() method of java.text.MessageFormat class is used to set the new format element at the particular index in pattern of message format object by overriding the previous pattern.
 
Syntax:
public void setFormatByArgumentIndex(int argumentIndex,
                                     Format newFormat)
Parameters: This method takes the following argument as a parameter.
- argumentIndex :- this is the particular index where new format element is going to be placed.
- newFormat :- this is the new Format element which is going to be placed.
Return Value: This method has nothing to return.
Below are the examples to illustrate the setFormatByArgumentIndex() method:
Example 1:  
Java
| // Java program to demonstrate// setFormatByArgumentIndex() methodimportjava.text.*;importjava.util.*;importjava.io.*;publicclassGFG {    publicstaticvoidmain(String[] argv)    {        // creating and initializing  MessageFormat        MessageFormat mf            = newMessageFormat("{1, date, #}, {3, number, #.##}, {5, time}");        // display the current pattern        System.out.println("old pattern : "                           + mf.toPattern());        // getting all the format element        // used in MessageFormat Object        Format[] formats = mf.getFormatsByArgumentIndex();        // setting the new format element        // at particular index        // using setFormatByArgumentIndex() method        for(inti = 0; i < formats.length; i++)            mf.setFormatByArgumentIndex(i, formats[1]);        // display the result        System.out.println("\nnew pattern : "                           + mf.toPattern());    }} | 
old pattern : {1,date, #}, {3,number, #0.##}, {5,time}
new pattern : {1,date, #}, {3,date, #}, {5,date, #}
Example 2:
Java
| // Java program to demonstrate// setFormatByArgumentIndex() methodimportjava.text.*;importjava.util.*;importjava.io.*;publicclassGFG {    publicstaticvoidmain(String[] argv)    {        // creating and initializing  MessageFormat        MessageFormat mf            = newMessageFormat("{1, date, #}, {3, number, #.##}, {5, time}");        // display the current pattern        System.out.println("old pattern : "                           + mf.toPattern());        // creating and initializing new Format element        Format fm = NumberFormat.getInstance();        // setting the new format element        // at particular index        // using setFormatByArgumentIndex() method        for(inti = 0; i < 6; i++)            mf.setFormatByArgumentIndex(i, fm);        // display the result        System.out.println("\nnew pattern : "                           + mf.toPattern());    }} | 
old pattern : {1,date, #}, {3,number, #0.##}, {5,time}
new pattern : {1,number}, {3,number}, {5,number}


 
                                    







