# Polymorphism — Core Java

Source: https://www.geekswithgeeks.com/en/core-java/java-polymorphism

> Hold subtype objects through a supertype reference and let the JVM pick the overridden method at runtime via dynamic dispatch.

## One reference, many types

A variable of a supertype can hold any subtype object. When you call an overridden method, the JVM dispatches to the **actual object's** version at runtime — not the reference type's.

## In action

The loop below prints `woof` then `meow` even though every element is typed as `Animal`.

```java
List<Animal> zoo = List.of(new Dog(), new Cat());
for (Animal a : zoo) System.out.println(a.sound());
```

Output:

```
woof
meow
```