Double decimal formatting in Java

With Java 8, you can use format method..: -

System.out.format("%.2f", 4.0); // OR

System.out.printf("%.2f", 4.0); 

• f is used for floating point value..
• 2 after decimal denotes, number of decimal places after .

For most Java versions, you can use DecimalFormat: -

    DecimalFormat formatter = new DecimalFormat("#0.00");
    double d = 4.0;
    System.out.println(formatter.format(d));

One of the way would be using NumberFormat.

NumberFormat formatter = new DecimalFormat("#0.00");     
System.out.println(formatter.format(4.0));

Output:

4.00