Question

The parameter in the equals() method is of type Object, which means the parameter in the equals() method we write must be of type Object. How can we treat the parameter as the type we need so we can access its instance variables?

Answer 1

In Java, the equals() method can be used to compare two objects for equality.

To access the instance variables of the parameter in the equals() method, we can cast it to the appropriate type using the instance of operator.

Step-by-step explanation:

The equals() method compares two strings, and returns true if the strings are equal, and false if not.

Since the parameter in the equals() method is of type Object, it's necessary to cast it to the appropriate type in order to access its instance variables.

To treat the parameter as the type we need, we can use the instanceof operator to check if the parameter is an instance of that type.

If it is, we can then cast it to that type and access its instance variables.

Here's an example:

public boolean equals(Object obj) {
if (obj instanceof MyClass) {
MyClass other = (MyClass) obj;
// access instance variables of other
}
return false;
}