OptionalLong orElseGet() method in Java with examples
The orElseGet(java.util.function.LongSupplier) method helps us to get the value in this OptionalLong object. If a value is not present in this OptionalLong, then this method returns the result produced by the supplying function, passed as the parameter
Syntax:
public long orElseGet(LongSupplier supplier)
Parameters: This method accepts the supplying function that produces a value to be returned.
Return value: This method returns the long value, if present, otherwise the result produced by the supplying function.
Exception: This method throw NullPointerException if no value is present and the supplying function is null.
Below programs illustrate orElseGet(java.util.function.LongSupplier) method:
Program 1:
Java
// Java program to demonstrate // OptionalLong.orElseGet(LongSupplier) method import java.util.OptionalLong; public class GFG { public static void main(String[] args) { // create a OptionalLong OptionalLong oplong = OptionalLong.of( 2134 ); // get value using orElseGet long value = oplong.orElseGet(() -> getlongValue()); // print value System.out.println("value: " + value); } public static long getlongValue() { return 3242 + 123 ; } } |
value: 2134
Program 2:
Java
// Java program to demonstrate // OptionalLong.orElseGet(LongSupplier) method import java.util.OptionalLong; public class GFG { public static void main(String[] args) { // create a OptionalLong OptionalLong oplong = OptionalLong.empty(); // get value using orElseGet long value = oplong.orElseGet(() -> getlongValue()); // print value System.out.println("value: " + value); } public static long getlongValue() { return 3242 * 234 ; } } |
value: 758628
References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalLong.html#orElseGet(java.util.function.LongSupplier)
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