Two Decimal Places Java

When a double data type is used in Java before a variable, this indicates 15 digits after decimal point. However, there are situations when we only require 2 decimal places after the decimal point, such as when representing rupees or other units. So, along with a suitable example and other Java applications, we will examine how to show double values with two decimal places in this part.

Java offers the three methods listed below for displaying double with two decimal places:

1. Using the DecimalFormat ("0.00")
2. Using the Method of String.format() ("%.2f")
3. Using the BigDecimal

Let's go over each of these methods individually.

Using DecimalFormat Class

The NumberFormat class's concrete subtype, Java DecimalFormat, class is used to format decimal numbers. The setRoundingMode() method of the class enables the presentation of double numbers with up to two decimal places.

Syntax:

public void setRoundingMode(RoundingMode roundingMode) 

It overrides the setRoundingMode() function of the NumberFormat class and accepts the rounding mode as a parameter. If no roundingMode is specified, NullPointerException is thrown.

The format() function from the class DecimalFormat was also used by us. In order to create a string, it formats a string.

Syntax:

public StringBuffer format(double number, StringBuffer result, FieldPosition fieldPosition) 

Three inputs are taken into account by the method: number, result, and location. The latter two variables, however, are not required. The formatted string of numbers is what is returned. If roundingMode gets set to UNNECESSARY, the procedure throws an ArithmeticException.

TwoDecimalPlaceDemo1.java

import java.math.RoundMode;  
import java.text.TheDecimalFormat;  
public class TwoDecimalPlaceDemo1   
{  
// DecimalFormat class constructor
private static final TheDecimalFormat df = new TheDecimalFormat("0.00");  
public static void main(String args[])   
{  
// declaring a double-type number
double num = 123.9876543567;  
System.out.println("The Double Number is: " + numb);  
System.out.println("The Double Number is: " + df.format(numb));    //123.99  
//TheDecimalFormat, RoundingMode is the default. HALF EVEN
df.setRoundMode(RoundMode.DOWN);  
System.out.println("\nBefore The Rounding: " + df.format(numb));  //123.98  
df.setRoundMode(RoundMode.UP);  
System.out.println("After The Rounding Up: " + df.format(numb));    //123.99  
}  
}  

Output:

The Double Number is: 123.9876543567
The Double Number is: 123.99


Before The Rounding: 123.98
After The Rounding Up: 123.99

Using The Method String.format()

The format() function is likewise available in Java for formatting numbers. It is a member of the String class. The method allows for the appropriate formatting of any integer or string.

Lets use %.2f as format the number and change it to two decimal places. Note that using the String.format() function to round a number results in a half-up rounding.

Syntax:

public static String format(String format, Object... args)

Two parameters are accepted by the method:

format: We need a string that has been formatted.

args: The parameters which the format specifiers inside the format string are referring to are listed as args.

The formatted string is what it gives back. If the format string has unlawful syntax, it throws an IllegalFormatException. If the format is set to null, it also raises a NullPointerException.

TwoDecimalPlaceDemo2.java

public class TwoDecimalPlaceDemo2  
{  
public static void main(String args[])   
{  
// declaring a double-type number
double numb = 10.98765432167;  
System.out.println("The Double Number is: " + numb);  
// For two decimal places, you can choose from the following two statements, and both get the same outcome.
System.out.println("The Double Number is: " + String.format("%.2f", numb));  
System.out.format("The Double Number is: %.2f", numb);  
}  
}  

Output:

The Double Number is: 10.98765432167
The Double Number is: 10.99
The Double Number is: 10.99

Using the BigDecimal

For showing a number with one to two decimal places, we can alternatively utilise the Java BigDecimal Class. It is a part of Java.math. BigDecimal bundle It implements the ComparableBigDecimal> interface and extends the Number class.

The setScale() method is provided by the class. The following is the syntax:

setScale(int newScale, RoundingMode roundingMode)

The procedure accepts two of the parameters:

The newScale: The scaling of such BigDecimal value that will be returned is newScale.

The roundingMode: The rounding technique we intend to use.

It yields the BigDecimal for whom the unscaled value is calculated simply multiplication or division that BigDecimal's unoptimized values even by correction factors of ten to retain its overall value. The scale is the provided number.

If RoundingMode gets set to UNNECESSARY, the procedure throws the ArithmeticException. An enum that offers the RoundingMode mentioned above is called RoundingMode. BigDecimal is another technique we've employed in this program.

BigDecimal.doubleValue() is changed into a double number. Here's an illustration.

TwoDecimalPlaceDemo3.java

import java.math.TheBigDecimal;  
import java.math.RoundMode;  
public class TwoDecimalPlaceDemo3   
{  
public static void main(String args[])   
{  
// declaring a double-type number 
double numb = 12.4565652239;  
System.out.println("The Double Number is: " + numb);  
TheBigDecimal bigd = new TheBigDecimal(numb).setScale(2, RoundMode.HALF_UP);  
double newNumb = bigd.doubleValue();  
System.out.println("To the nearest two decimal places: " + newNumb);  
}  
}  

Output:

The Double Number is: 12.4565652239
To the nearest two decimal places: 12.46