BigDecimal sqrt() Method in Java with Examples

The java.math.BigDecimal.sqrt(MathContext mc) is an inbuilt function added in Java SE 9 & JDK 9 which returns BigDecimal value of square root of a BigDecimal on which sqrt() method is applied with rounding according to the context settings.

Syntax:

public BigDecimal sqrt(MathContext mc)

Parameters: This method accepts a parameter mc of type MathContext for context settings.

Return Value: This method returns an approximation to the square root of this with rounding according to the context settings.

Exception: The method throws ArithmeticException for following conditions.

• If BigDecimal number is less than zero.
• If an exact result is requested (Precision = 0) and there is no finite decimal expansion of the exact result.
• If the exact result cannot fit in Precision digits.

Note: This method is only available from JDK 9.

Below programs are used to illustrate the sqrt() method of BigDecimal:

Example 1:

// Java program to demonstrate sqrt() method

import java.math.*;

public class GFG {

    public static void main(String[] args)
    {

        // Creating a BigDecimal object
        BigDecimal a, squareRoot;

        a = new BigDecimal("100000000000000000000");

        // Set precision to 10
        MathContext mc
            = new MathContext(10);

        // calculate square root of bigDecimal
        // using sqrt() method
        squareRoot = a.sqrt(mc);

        // print result
        System.out.println("Square root value of " + a
                           + " is " + squareRoot);
    }
}

Output:

Square root value of 100000000000000000000 is 1.000000000E+10

Example 2: Showing Exception thrown by sqrt() method.

// Java program to demonstrate sqrt() method

import java.math.*;

class GFG {

    public static void main(String[] args)
    {

        // Creating a BigDecimal object
        BigDecimal a, squareRoot;

        a = new BigDecimal("-4");

        // Set precision to 10
        MathContext mc
            = new MathContext(10);

        // calculate square root of bigDecimal
        // using sqrt() method
        try {
            squareRoot = a.sqrt(mc);

            // print result
            System.out.println("Square root"
                               + " value of " + a
                               + " is " + squareRoot);
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

Output:

java.lang.ArithmeticException: Attempted square root of negative BigDecimal

References: https://docs.oracle.com/javase/9/docs/api/java/math/BigDecimal.html#sqrt-java.math.MathContext-