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java/inheritance/Animal.java

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+public class Animal {
+  public String name;
+
+  public Animal(String name) {
+    this.name = name;
+  }
+
+  public void make_sound() {
+    System.out.println(this.name + ":");
+  }
+}

java/inheritance/Cat.java

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+// make the class cat inherit from Animal
+public class Cat extends Animal {
+  // java requires an explicit constructor when the supertype awaits parameters in the constructor
+  public Cat(String name) {
+    // call supertype constructor
+    super(name);
+  }
+
+  // override make_sound
+  public void make_sound() {
+    // optional: call the parent class function
+    super.make_sound();
+
+    // add additional functionality
+    System.out.println("meow");
+  }
+}

java/inheritance/Dog.java

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+public class Dog extends Animal {
+  // java requires an explicit constructor when the supertype awaits parameters in the constructor
+  public Dog(String name) {
+    // call supertype constructor
+    super(name);
+  }
+
+  // override the method make_sound
+  public void make_sound() {
+    // implement own functionality
+    System.out.println("doggo " + this.name + " says:");
+    System.out.println("woof!");
+  }
+}

java/inheritance/Program.java

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+public class Program {
+  public static void main(String[] args) {
+    Dog d = new Dog("buster");
+    Cat c = new Cat("mittens");
+
+    d.make_sound();
+    c.make_sound();
+  }
+}

java/inheritance/README.md

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+# Inheritance
+
+Relevant files:
+
+- [Program.java](./Program.java)
+- [Animal.java](./Animal.java)
+- [Cat.java](./Cat.java)
+- [Dog.java](./Dog.java)