Sometimes in Competitive programming, it is essential to print the output in a given specified format. Most users are familiar with printf function in C. Let us see discuss how we can format the output in Java:
This is the easiest of all methods as this is similar to printf in C. Note that System.out.print() and System.out.println() take a single argument, but printf() may take multiple arguments.
// A Java program to demonstrate working of printf() in Java class JavaFormatter1 { public static void main(String args[]) { int x = 100 ; System.out.printf( "Printing simple integer: x = %d\n" , x); // this will print it upto 2 decimal places System.out.printf( "Formatted with precison: PI = %.2f\n" , Math.PI); float n = 5 .2f; // automatically appends zero to the rightmost part of decimal System.out.printf( "Formatted to specific width: n = %.4f\n" , n); n = 2324435 .3f; // here number is formatted from right margin and occupies a // width of 20 characters System.out.printf( "Formatted to right margin: n = %20.4f\n" , n); } } |
Printing simple integer: x = 100 Formatted with precison: PI = 3.14 Formatted to specific width: n = 5.2000 Formatted to right margin: n = 2324435.2500
System.out.format() is equivalent to printf() and can also be used.
DecimalFormat is used to format decimal numbers.
// Java program to demonstrate working of DecimalFormat import java.text.DecimalFormat; class JavaFormatter2 { public static void main(String args[]) { double num = 123.4567 ; // prints only numeric part of a floating number DecimalFormat ft = new DecimalFormat( "####" ); System.out.println( "Without fraction part: num = " + ft.format(num)); // this will print it upto 2 decimal places ft = new DecimalFormat( "#.##" ); System.out.println( "Formatted to Give precison: num = " + ft.format(num)); // automatically appends zero to the rightmost part of decimal // instead of #,we use digit 0 ft = new DecimalFormat( "#.000000" ); System.out.println( "appended zeroes to right: num = " + ft.format(num)); // automatically appends zero to the leftmost of decimal number // instead of #,we use digit 0 ft = new DecimalFormat( "00000.00" ); System.out.println( "formatting Numeric part : num = " +ft.format(num)); // formatting money in dollars double income = 23456.789 ; ft = new DecimalFormat( "$###,###.##" ); System.out.println( "your Formatted Dream Income : " + ft.format(income)); } } |
Without fraction part: num = 123 Formatted to Give precison: num = 123.46 appended zeroes to right: num = 123.456700 formatting Numeric part : num = 00123.46 your Formatted Dream Income : $23,456.79
This class is present in java.text package.
// Java program to demonstrate working of SimpleDateFormat import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; class Formatter3 { public static void main(String args[]) throws ParseException { // Formatting as per given pattern in the argument SimpleDateFormat ft = new SimpleDateFormat( "dd-MM-yyyy" ); String str = ft.format( new Date()); System.out.println( "Formatted Date : " + str); // parsing a given String str = "02/18/1995" ; ft = new SimpleDateFormat( "MM/dd/yyyy" ); Date date = ft.parse(str); // this will print the date as per parsed string System.out.println( "Parsed Date : " + date); } } |
Formatted Date : 09-08-2018 Parsed Date : Sat Feb 18 00:00:00 UTC 1995
References:
https://docs.oracle.com/
https://docs.oracle.com/
http://docs.oracle.com/javase/
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