Optional ofNullable() method in Java with examples
The ofNullable() method of java.util.Optional class in Java is used to get an instance of this Optional class with the specified value of the specified type. If the specified value is null, then this method returns an empty instance of the Optional class.
Syntax:
public static <T> Optional<T> ofNullable(T value)
Parameters: This method accepts value as parameter of type T to create an Optional instance with this value. It can be null.
Return value: This method returns an instance of this Optional class with the specified value of the specified type. If the specified value is null, then this method returns an empty instance of the Optional class.
Below programs illustrate ofNullable() method:
Program 1:
// Java program to demonstrate // Optional.ofNullable() method import java.util.*; public class GFG { public static void main(String[] args) { // create a Optional Optional<Integer> op1 = Optional.ofNullable( 9455 ); // print value System.out.println( "Optional 1: " + op1); } } |
Optional 1: Optional[9455]
Program 2:
// Java program to demonstrate // Optional.ofNullable() method import java.util.*; public class GFG { public static void main(String[] args) { // create a Optional Optional<String> op2 = Optional.ofNullable( null ); // print value System.out.println( "Optional 2: " + op2); } } |
Optional 2: Optional.empty
Reference: https://docs.oracle.com/javase/9/docs/api/java/util/Optional.html#ofNullable-T-
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