Java 8 | BigInteger longValueExact() Method with Examples
java.math.BigInteger.longValueExact() was introduced in Java 8. It is an inbuilt function which converts the value of BigInteger to a long and checks for lost information. If the value of BigInteger is greater than 9,223,372,036,854,775,807 or less than -9,223,372,036,854,775,808; the method will throw ArithmeticException as BigInteger doesn’t fit in long range.
Syntax:
public long longValueExact()
Return Value: This method returns the long value of this BigInteger.
Exception: The method throws ArithmeticException if the value of BigInteger is greater than 9,223,372,036,854,775,807 or less than -9,223,372,036,854,775,808; as this range doesn’t fit in long range.
Example:
Input: 98169894145 Output: 98169894145 Explanation: 98169894145 is given as input which is BigInteger and long value of 98169894145 is 98169894145 Input: -65416518651 Output: -65416518651 Explanation: -65416518651 is given as input which is BigInteger and long value of -65416518651 is -65416518651 Input: 10000000000000000000 Output: ArithmeticException Explanation: When 10000000000000000000 is tried to convert to long, since 10000000000000000000 > 9,223,372,036,854,775,807 (greater than a long's range), therefore it throws an arithmetic exception.
Below programs illustrates longValueExact() method of BigInteger class:
Program 1: To demonstrate longValueExact() method for positive number <9,223,372,036,854,775,807
// Java program to demonstrate longValueExact()// method of BigInteger Class  import java.math.*;  public class GFG {      public static void main(String[] args)    {        // Creating a BigInteger object        BigInteger big;        big = new BigInteger("98169894145");          // print value of BigInteger        System.out.println("BigInteger value : "                           + big);          // convert big to the long value        long b1 = big.longValueExact();          // print long value        System.out.println("long converted value : "                           + b1);    }} |
BigInteger value : 98169894145 long converted value : 98169894145
Program 2: To demonstrate longValueExact() method for negative number >-9,223,372,036,854,775,808
// Java program to demonstrate longValueExact()// method of BigInteger Class  import java.math.*;  public class GFG {      public static void main(String[] args)    {          // Creating a BigInteger object        BigInteger big = new BigInteger("-65416518651");          // print value of BigInteger        System.out.println("BigInteger value : "                           + big);          // convert big to the long value        long b1 = big.longValueExact();          // print long value        System.out.println("long converted value : "                           + b1);    }} |
BigInteger value : -65416518651 long converted value : -65416518651
Program 3: To demonstrate longValueExact() method for negative number <-9,223,372,036,854,775,808. It will throw Arithmetic Exception
// Java program to demonstrate longValueExact()// method of BigInteger Class  import java.math.*;  public class GFG {      public static void main(String[] args)    {          // Creating a BigInteger object        BigInteger big = new BigInteger("-10000000000000000000");          // print value of BigInteger        System.out.println("BigInteger value : "                           + big);          try {            // convert big to the long value            long b1 = big.longValueExact();              // print long value            System.out.println("long converted value : "                               + b1);        }        catch (Exception e) {            System.out.println("Exception: " + e);        }    }} |
BigInteger value : -10000000000000000000 Exception: java.lang.ArithmeticException: BigInteger out of long range
Program 4: To demonstrate longValueExact() method for positive number >9,223,372,036,854,775,807. It will throw Arithmetic Exception
// Java program to demonstrate longValueExact()// method of BigInteger Class  import java.math.*;  public class GFG {      public static void main(String[] args)    {          // Creating a BigInteger object        BigInteger big = new BigInteger("10000000000000000000");          // print value of BigInteger        System.out.println("BigInteger value : "                           + big);          try {            // convert big to the long value            long b1 = big.longValueExact();              // print long value            System.out.println("long converted value : "                               + b1);        }        catch (Exception e) {            System.out.println("Exception: " + e);        }    }} |
BigInteger value : 10000000000000000000 Exception: java.lang.ArithmeticException: BigInteger out of long range
Reference: https://docs.oracle.com/javase/8/docs/api/java/math/BigInteger.html#longValueExact–
