The java.math.BigDecimal.longValue() is an in-built function which converts this BigDecimal to a long value. This function discards any fractional part of this BigDecimal. The function returns only the lower-order 64 bits when the result of the conversion is too big to be represented as a long value.
Syntax:
public long longValue()
Parameters: This function accepts no parameters.
Return Value: This function returns the long value of this BigDecimal.
Examples:
Input : 1987812456121.176 Output : 1987812456121 Input : "721111" Output : 721111
Below programs illustrate the use of java.math.BigDecimal.longValue() method:
Program 1:
// Java program to illustrate// longValue() methodimport java.math.*;import java.io.*;  class GFG {    public static void main(String[] args)    {        // Creating 2 BigDecimal Objects        BigDecimal b1, b2;          // Assigning values to b1, b2        b1 = new BigDecimal("1987812456121.176");        b2 = new BigDecimal("721111");          // Displaying their respective Long Values        System.out.println("The Long Value of " + b1 +        " is " + b1.longValue());        System.out.println("The Long Value of " + b2 +         " is " + b2.longValue());    }} |
The Long Value of 1987812456121.176 is 1987812456121 The Long Value of 721111 is 721111
Note: Information regarding the overall magnitude and precision of large this BigDecimal values might be lost during the course of conversion by this function. As a consequence, a result with the opposite sign might be returned.
Program 2: Below program illustrates a scenario when the function returns a result with the opposite sign.
// Java program to illustrate// longValue() methodimport java.math.*;import java.io.*;  class GFG {    public static void main(String[] args)    {        // Creating 2 BigDecimal Objects        BigDecimal b1, b2;          // Assigning values to b1, b2        b1 = new BigDecimal("267694723232435121868");        b2 = new BigDecimal("72111184561789104423");          // Displaying their respective Long Values        System.out.println("The Long Value of " + b1 +         " is " + b1.longValue());        System.out.println("The Long Value of " + b2 +         " is " + b2.longValue());    }} |
The Long Value of 267694723232435121868 is -9006437873208152372 The Long Value of 72111184561789104423 is -1675791733049102041
Reference:https://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html#longValue()
