OptionalDouble help us to create an object which may or may not contain a Double value. The equals(Object obj) method help us to compare this OptionalDouble object with the passed object as a parameter and it returns true if objects are equal.
The other object is considered equal to this OptionalDouble if:
- it is also an OptionalDouble and;
- both instances have no value present or;
- the present values are “equal to” each other via ==.
Syntax:
public boolean equals(Object obj)
Parameters: This method accepts an obj which is an object to be tested for equality.
Return value: This method returns true if the other object is “equal to” this object otherwise false.
Below programs illustrate equals(Object obj) method:
Program 1:
| // Java program to demonstrate// OptionalDouble.equals(Object obj) method importjava.util.OptionalDouble; publicclassGFG {     publicstaticvoidmain(String[] args)    {         // Create first OptionalDouble object        OptionalDouble opDouble1            = OptionalDouble.of(452.13246);         System.out.println("OptionalDouble 1: "                           + opDouble1.toString());         // Create second OptionalDouble object        OptionalDouble opDouble2            = OptionalDouble.of(452.13246);         System.out.println("OptionalDouble 2: "                           + opDouble2.toString());         // Check if these two objects are equal        // using equals(Object obj)        System.out.println("Are both objects equal: "                           + opDouble1.equals(opDouble2));    }} | 
OptionalDouble 1: OptionalDouble[452.13246] OptionalDouble 2: OptionalDouble[452.13246] Are both objects equal: true
Program 2:
| // Java program to demonstrate// OptionalDouble.equals(Object obj) method importjava.util.OptionalDouble; publicclassGFG {     publicstaticvoidmain(String[] args)    {        // Create first OptionalDouble object        OptionalDouble opDouble1            = OptionalDouble.of(3179464.92);         System.out.println("OptionalDouble 1: "                           + opDouble1.toString());         // Create second OptionalDouble object        OptionalDouble opDouble2            = OptionalDouble.of(4521.3246);         System.out.println("OptionalDouble 2: "                           + opDouble2.toString());         // Check if these two objects are equal        // using equals(Object obj)        System.out.println("Are both objects equal: "                           + opDouble1.equals(opDouble2));    }} | 
OptionalDouble 1: OptionalDouble[3179464.92] OptionalDouble 2: OptionalDouble[4521.3246] Are both objects equal: false
References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalDouble.html#equals?(Object obj)

 
                                    







