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11.7. The Equals Method¶
If a parent class isn’t specified using the extends keyword, the class will inherit from the
Object class. What does a class inherit from the
Object class? One of the important things that gets inherited is the
equals(Object obj) method. This method is used to test if the current object and the passed object called
obj are equal. But what does that mean?
11.7.1. The Inherited Equals Method from Object¶
equals method that is inherited from the
Object class only returns true if the two objects references refer to the same object.
equals method inherited from the
Object class only returns true when the two references point to the same object as shown in the code above and figure 1 below.
11.7.2. String Overrides Equals¶
If you want to change how the inherited
equals method works you can override it so that the new method is called instead of the inherited one. The
String class overrides the inherited equals method to return true when the two objects have the same characters in the same order as shown in the code below.
11.7.3. Overriding the Inherited Equals Method¶
A class can override the inherited
equals method by providing a method with the same method signature (method name and parameter list) and return type. The provided method will be called instead of the inherited one, which is why we say that the new method overrides the inherited method. The
Person class below overrides the inherited
You can step through this code in the Java Visualizer by clicking on the following link: OverrideEquals Ex.