Polymorphism
The word “polymorphism” means “many forms.” In object-oriented programming, polymorphism is useful when you want to create multiple forms with the same name of a single entity. To implement polymorphism in Java, we use two concepts: method overloading and method overriding.
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Method overloading is implemented within the same class, where we have multiple methods with the same name but different parameters.
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Method overriding is implemented using inheritance, where we can have multiple methods with the same name in the parent class and the child class.
Source Code: Polymorphism.java
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// Superclass
class Person {
void displayInfo() {
System.out.println("This is a person.");
}
}
// Subclass
class Student extends Person {
// Overriding method
@Override
void displayInfo() {
System.out.println("This is a student.");
}
}
// Another Subclass
class Teacher extends Person {
@Override
void displayInfo() {
System.out.println("This is a teacher.");
}
}
// Main class
public class Polymorphism {
public static void main(String[] args) {
// Polymorphism: same reference, different object types
Person p1 = new Person();
Person p2 = new Student(); // upcasting
Person p3 = new Teacher(); // upcasting
// Call the same method on all objects
p1.displayInfo(); // Calls Person version
p2.displayInfo(); // Calls Student version
p3.displayInfo(); // Calls Teacher version
}
}Result:
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