diff --git a/assignment2/Question1/HalfMarathon.java b/assignment2/Question1/HalfMarathon.java
new file mode 100644
index 0000000..ca28cbb
--- /dev/null
+++ b/assignment2/Question1/HalfMarathon.java
@@ -0,0 +1,24 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Running class which is the subclass of the Sport class
+ */
+
+public class HalfMarathon extends Marathon {
+	/**
+	 * Constructor. Half marathon always has player number 99 and length of 21.0975
+	 */
+	public HalfMarathon() {
+		super(99, 21.0975);
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testHalfMarathon() {
+		HalfMarathon hm = new HalfMarathon();
+		System.out.println(hm.getLength() == 21.0975);
+		System.out.println(hm.getPlayerNumber() == 99);
+		System.out.println(hm.isFun() == false);
+	}
+}
diff --git a/assignment2/Question1/Marathon.java b/assignment2/Question1/Marathon.java
new file mode 100644
index 0000000..29d3102
--- /dev/null
+++ b/assignment2/Question1/Marathon.java
@@ -0,0 +1,43 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Running class which is the subclass of the Sport class
+ */
+
+public class Marathon extends Running {
+	/**
+	 * Constructor.
+	 *
+	 * @param playerNumber
+	 * 	  the player number
+	 * @param length
+	 * 	  the length of the marathon
+	 */
+	public Marathon(int playerNumber, double length) {
+		super(playerNumber, length);
+	}
+
+	/**
+	 * Constructor. Always set the length to 42.195
+	 *
+	 * @param playerNumber
+	 */
+	public Marathon(int playerNumber) {
+		this(playerNumber, 42.195);
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testMarathon() {
+		Marathon m1 = new Marathon(1, 39.39);
+		System.out.println(m1.getLength() == 39.39);
+		System.out.println(m1.getPlayerNumber() == 1);
+		System.out.println(m1.isFun() == false);
+
+		Marathon m2 = new Marathon(2);
+		System.out.println(m2.getLength() == 42.195);
+		System.out.println(m2.getPlayerNumber() == 2);
+		System.out.println(m2.isFun() == false);
+	}
+}
diff --git a/assignment2/Question1/Running.java b/assignment2/Question1/Running.java
new file mode 100644
index 0000000..5b1b77e
--- /dev/null
+++ b/assignment2/Question1/Running.java
@@ -0,0 +1,50 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Running class which is the subclass of the Sport class
+ */
+
+public class Running extends Sport {
+	/**
+	 * The length of the running.
+	 */
+	private double length;
+
+	/**
+	 * Constructor.
+	 *
+	 * @param playerNumber the player number of the running.
+	 * @param length       the length of the running
+	 */
+	public Running(int playerNumber, double length) {
+		super(playerNumber);
+		this.length = length;
+	}
+
+	/**
+	 * Getter for the length of the running.
+	 */
+	public double getLength() {
+		return length;
+	}
+
+	/**
+	 * Running is not fun.
+	 *
+	 * @return false
+	 */
+	@Override
+	public boolean isFun() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testRunning() {
+		Running r1 = new Running(1, 1.5);
+		System.out.println(r1.getPlayerNumber() == 1);
+		System.out.println(r1.getLength() == 1.5);
+		System.out.println(r1.isFun() == false);
+	}
+}
diff --git a/assignment2/Question1/Sport.java b/assignment2/Question1/Sport.java
new file mode 100644
index 0000000..ac50875
--- /dev/null
+++ b/assignment2/Question1/Sport.java
@@ -0,0 +1,46 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Sport class.
+ */
+
+public class Sport {
+	private int playerNumber;
+
+	/**
+	 * Constructor.
+	 *
+	 * @param playerNumber
+	 */
+	public Sport(int playerNumber) {
+		this.playerNumber = playerNumber;
+	}
+
+	/**
+	 * Getter for playerNumber.
+	 *
+	 * @return playerNumber
+	 */
+	public int getPlayerNumber() {
+		return playerNumber;
+	}
+
+	/**
+	 * Whether the sport is fun or not. Some sport are fun and some sports are not
+	 * fun. By default the sport is not fun.
+	 *
+	 * @return true if the sport is fun, false if the sport is not fun.
+	 */
+	public boolean isFun() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testSport() {
+		Sport sport = new Sport(10);
+		System.out.println(sport.getPlayerNumber() == 10);
+		System.out.println(sport.isFun() == false);
+	}
+}
diff --git a/assignment2/Question1/Start.java b/assignment2/Question1/Start.java
new file mode 100644
index 0000000..f384976
--- /dev/null
+++ b/assignment2/Question1/Start.java
@@ -0,0 +1,9 @@
+public class Start {
+	public static void main(String[] args) {
+		Sport.testSport();
+		Tennis.testTennis();
+		Running.testRunning();
+		Marathon.testMarathon();
+		HalfMarathon.testHalfMarathon();
+	}
+}
diff --git a/assignment2/Question1/Tennis.java b/assignment2/Question1/Tennis.java
new file mode 100644
index 0000000..47b5088
--- /dev/null
+++ b/assignment2/Question1/Tennis.java
@@ -0,0 +1,33 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Tennis class which is the subclass of the Sport class.
+ */
+
+public class Tennis extends Sport {
+	/**
+	 * Constructor. Tennis has 2 player.
+	 */
+	public Tennis() {
+		super(2);
+	}
+
+	/**
+	 * Tennis is fun.
+	 *
+	 * @return true
+	 */
+	@Override
+	public boolean isFun() {
+		return true;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testTennis() {
+		Tennis t = new Tennis();
+		System.out.println(t.getPlayerNumber() == 2);
+		System.out.println(t.isFun() == true);
+	}
+}
diff --git a/assignment2/Question2/HalfMarathon.java b/assignment2/Question2/HalfMarathon.java
new file mode 100644
index 0000000..ca28cbb
--- /dev/null
+++ b/assignment2/Question2/HalfMarathon.java
@@ -0,0 +1,24 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Running class which is the subclass of the Sport class
+ */
+
+public class HalfMarathon extends Marathon {
+	/**
+	 * Constructor. Half marathon always has player number 99 and length of 21.0975
+	 */
+	public HalfMarathon() {
+		super(99, 21.0975);
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testHalfMarathon() {
+		HalfMarathon hm = new HalfMarathon();
+		System.out.println(hm.getLength() == 21.0975);
+		System.out.println(hm.getPlayerNumber() == 99);
+		System.out.println(hm.isFun() == false);
+	}
+}
diff --git a/assignment2/Question2/Marathon.java b/assignment2/Question2/Marathon.java
new file mode 100644
index 0000000..29d3102
--- /dev/null
+++ b/assignment2/Question2/Marathon.java
@@ -0,0 +1,43 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Running class which is the subclass of the Sport class
+ */
+
+public class Marathon extends Running {
+	/**
+	 * Constructor.
+	 *
+	 * @param playerNumber
+	 * 	  the player number
+	 * @param length
+	 * 	  the length of the marathon
+	 */
+	public Marathon(int playerNumber, double length) {
+		super(playerNumber, length);
+	}
+
+	/**
+	 * Constructor. Always set the length to 42.195
+	 *
+	 * @param playerNumber
+	 */
+	public Marathon(int playerNumber) {
+		this(playerNumber, 42.195);
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testMarathon() {
+		Marathon m1 = new Marathon(1, 39.39);
+		System.out.println(m1.getLength() == 39.39);
+		System.out.println(m1.getPlayerNumber() == 1);
+		System.out.println(m1.isFun() == false);
+
+		Marathon m2 = new Marathon(2);
+		System.out.println(m2.getLength() == 42.195);
+		System.out.println(m2.getPlayerNumber() == 2);
+		System.out.println(m2.isFun() == false);
+	}
+}
diff --git a/assignment2/Question2/Running.java b/assignment2/Question2/Running.java
new file mode 100644
index 0000000..5b1b77e
--- /dev/null
+++ b/assignment2/Question2/Running.java
@@ -0,0 +1,50 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Running class which is the subclass of the Sport class
+ */
+
+public class Running extends Sport {
+	/**
+	 * The length of the running.
+	 */
+	private double length;
+
+	/**
+	 * Constructor.
+	 *
+	 * @param playerNumber the player number of the running.
+	 * @param length       the length of the running
+	 */
+	public Running(int playerNumber, double length) {
+		super(playerNumber);
+		this.length = length;
+	}
+
+	/**
+	 * Getter for the length of the running.
+	 */
+	public double getLength() {
+		return length;
+	}
+
+	/**
+	 * Running is not fun.
+	 *
+	 * @return false
+	 */
+	@Override
+	public boolean isFun() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testRunning() {
+		Running r1 = new Running(1, 1.5);
+		System.out.println(r1.getPlayerNumber() == 1);
+		System.out.println(r1.getLength() == 1.5);
+		System.out.println(r1.isFun() == false);
+	}
+}
diff --git a/assignment2/Question2/Sport.java b/assignment2/Question2/Sport.java
new file mode 100644
index 0000000..ac50875
--- /dev/null
+++ b/assignment2/Question2/Sport.java
@@ -0,0 +1,46 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Sport class.
+ */
+
+public class Sport {
+	private int playerNumber;
+
+	/**
+	 * Constructor.
+	 *
+	 * @param playerNumber
+	 */
+	public Sport(int playerNumber) {
+		this.playerNumber = playerNumber;
+	}
+
+	/**
+	 * Getter for playerNumber.
+	 *
+	 * @return playerNumber
+	 */
+	public int getPlayerNumber() {
+		return playerNumber;
+	}
+
+	/**
+	 * Whether the sport is fun or not. Some sport are fun and some sports are not
+	 * fun. By default the sport is not fun.
+	 *
+	 * @return true if the sport is fun, false if the sport is not fun.
+	 */
+	public boolean isFun() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testSport() {
+		Sport sport = new Sport(10);
+		System.out.println(sport.getPlayerNumber() == 10);
+		System.out.println(sport.isFun() == false);
+	}
+}
diff --git a/assignment2/Question2/SportsCourt.java b/assignment2/Question2/SportsCourt.java
new file mode 100644
index 0000000..03954e5
--- /dev/null
+++ b/assignment2/Question2/SportsCourt.java
@@ -0,0 +1,37 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the class of SportsCourt.
+ */
+
+public class SportsCourt {
+	private Sport sport;
+
+	/**
+	 * Constructor.
+	 * 
+	 * @param sport
+	 */
+	public SportsCourt(Sport sport) {
+		this.sport = sport;
+	}
+
+	/**
+	 * Getter of sport.
+	 *
+	 * @return sport
+	 */
+	public Sport playSport() {
+		return sport;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testSportsCourt() {
+		HalfMarathon hm1 = new HalfMarathon();
+		SportsCourt sc1 = new SportsCourt(hm1);
+		HalfMarathon hm2 = (HalfMarathon) sc1.playSport();
+		System.out.println(sc1.playSport() == hm2);
+	}
+}
diff --git a/assignment2/Question2/Start.java b/assignment2/Question2/Start.java
new file mode 100644
index 0000000..95c4990
--- /dev/null
+++ b/assignment2/Question2/Start.java
@@ -0,0 +1,10 @@
+public class Start {
+	public static void main(String[] args) {
+		Sport.testSport();
+		Tennis.testTennis();
+		Running.testRunning();
+		Marathon.testMarathon();
+		HalfMarathon.testHalfMarathon();
+		SportsCourt.testSportsCourt();
+	}
+}
diff --git a/assignment2/Question2/Tennis.java b/assignment2/Question2/Tennis.java
new file mode 100644
index 0000000..47b5088
--- /dev/null
+++ b/assignment2/Question2/Tennis.java
@@ -0,0 +1,33 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/03/04
+ * Description: This is the Tennis class which is the subclass of the Sport class.
+ */
+
+public class Tennis extends Sport {
+	/**
+	 * Constructor. Tennis has 2 player.
+	 */
+	public Tennis() {
+		super(2);
+	}
+
+	/**
+	 * Tennis is fun.
+	 *
+	 * @return true
+	 */
+	@Override
+	public boolean isFun() {
+		return true;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testTennis() {
+		Tennis t = new Tennis();
+		System.out.println(t.getPlayerNumber() == 2);
+		System.out.println(t.isFun() == true);
+	}
+}
diff --git a/assignment3/Question1/EuropeanRabbit.java b/assignment3/Question1/EuropeanRabbit.java
new file mode 100644
index 0000000..540cb5c
--- /dev/null
+++ b/assignment3/Question1/EuropeanRabbit.java
@@ -0,0 +1,43 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: European rabbit
+ */
+
+public class EuropeanRabbit extends Rabbit {
+	/**
+	 * Constructor.
+	 *
+	 * @param name   The name of the Rabbit.
+	 * @param weight The weight of the Rabbit.
+	 */
+	public EuropeanRabbit(String name, double weight) {
+		super(name, weight);
+	}
+
+	/**
+	 * Constructor. With default weight 2.0
+	 *
+	 * @param name The name of the Rabbit.
+	 */
+	public EuropeanRabbit(String name) {
+		this(name, 2.0);
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testEuropeanRabbit() {
+		// test first constructor
+		Rabbit rabbit = new EuropeanRabbit("Bugs Bunny");
+		System.out.println(rabbit.getName() == "Bugs Bunny");
+		System.out.println(rabbit.getWeight() == 2.0);
+		System.out.println(rabbit.isCookable() == true);
+
+		// test second constructor
+		Rabbit rabbit2 = new EuropeanRabbit("Daffy Duck", 3.0);
+		System.out.println(rabbit2.getName() == "Daffy Duck");
+		System.out.println(rabbit2.getWeight() == 3.0);
+		System.out.println(rabbit2.isCookable() == true);
+	}
+}
diff --git a/assignment3/Question1/FrankTheRabbit.java b/assignment3/Question1/FrankTheRabbit.java
new file mode 100644
index 0000000..96c14fa
--- /dev/null
+++ b/assignment3/Question1/FrankTheRabbit.java
@@ -0,0 +1,36 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: European rabbit
+ */
+
+public class FrankTheRabbit extends Rabbit {
+	/**
+	 * Constructor.
+	 *
+	 * With name "Frank" and weight of 100.0
+	 */
+	public FrankTheRabbit() {
+		super("Frank", 100.0);
+	}
+
+	/**
+	 * Frank rabbit can not be cooked.
+	 *
+	 * @return false
+	 */
+	@Override
+	public boolean isCookable() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testFrankTheRabbit() {
+		FrankTheRabbit frank = new FrankTheRabbit();
+		System.out.println(frank.getName() == "Frank");
+		System.out.println(frank.getWeight() == 100.0);
+		System.out.println(frank.isCookable() == false);
+	}
+}
diff --git a/assignment3/Question1/Human.java b/assignment3/Question1/Human.java
new file mode 100644
index 0000000..e39286d
--- /dev/null
+++ b/assignment3/Question1/Human.java
@@ -0,0 +1,36 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Human class
+ */
+
+public class Human extends Mammal {
+
+	/**
+	 * Constructor.
+	 * 
+	 * The Constructor take no argument. All human are named "Alice"
+	 */
+	public Human() {
+		super("Alice");
+	}
+
+	/**
+	 * Human cannot be cooked.
+	 *
+	 * @return false
+	 */
+	@Override
+	public boolean isCookable() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testHuman() {
+		Human human = new Human();
+		System.out.println(human.getName() == "Alice");
+		System.out.println(human.isCookable() == false);
+	}
+}
diff --git a/assignment3/Question1/LapinSauteChasseur.java b/assignment3/Question1/LapinSauteChasseur.java
new file mode 100644
index 0000000..216f06a
--- /dev/null
+++ b/assignment3/Question1/LapinSauteChasseur.java
@@ -0,0 +1,26 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Lapin Saute Chasseur
+ */
+
+public class LapinSauteChasseur extends EuropeanRabbit {
+	/**
+	 * Constructor.
+	 *
+	 * With name "Delicious" and has a weight of 0.5
+	 */
+	public LapinSauteChasseur() {
+		super("Delicious", 0.5);
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testLapinSauteChasseur() {
+		LapinSauteChasseur rabbit = new LapinSauteChasseur();
+		System.out.println(rabbit.getName() == "Delicious");
+		System.out.println(rabbit.getWeight() == 0.5);
+		System.out.println(rabbit.isCookable() == true);
+	}
+}
diff --git a/assignment3/Question1/Mammal.java b/assignment3/Question1/Mammal.java
new file mode 100644
index 0000000..1f76242
--- /dev/null
+++ b/assignment3/Question1/Mammal.java
@@ -0,0 +1,53 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Mammal class
+ */
+
+public class Mammal {
+	/**
+	 * Name of the mammal
+	 */
+	private String name;
+
+	/**
+	 * Constructor
+	 * 
+	 * @param name
+	 *             name of the mammal
+	 */
+	public Mammal(String name) {
+		this.name = name;
+	}
+
+	/**
+	 * Get the name of the mammal
+	 * 
+	 * @return name of the mammal
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Whether the mammal is can be cooked.
+	 * Some mammals can be cooked and some mammals cannot be cooked so for safety
+	 * reason the isCookable method just prints a message "Do not cook this!" and
+	 * returns false.
+	 *
+	 * @return false
+	 */
+	public boolean isCookable() {
+		System.out.println("Do not cook this!");
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testMammal() {
+		Mammal mammal = new Mammal("Mammal 1");
+		System.out.println(mammal.getName() == "Mammal 1");
+		System.out.println(mammal.isCookable() == false);
+	}
+}
diff --git a/assignment3/Question1/Rabbit.java b/assignment3/Question1/Rabbit.java
new file mode 100644
index 0000000..c1d8063
--- /dev/null
+++ b/assignment3/Question1/Rabbit.java
@@ -0,0 +1,54 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Rabbit class
+ */
+
+public class Rabbit extends Mammal {
+	/**
+	 * The weight of the rabbit.
+	 */
+	private double weight;
+
+	/**
+	 * Getter for the weight of the rabbit.
+	 *
+	 * @return the weight of the rabbit
+	 */
+	public double getWeight() {
+		return weight;
+	}
+
+	/**
+	 * Constructor.
+	 *
+	 * @param name
+	 * 	  the name of the rabbit
+	 * @param weight
+	 * 	  the weight of the rabbit
+	 */
+	public Rabbit(String name, double weight) {
+		super(name);
+		this.weight = weight;
+	}
+
+	/**
+	 * Rabbit can be cooked.
+	 *
+	 * return true
+	 */
+	@Override
+	public boolean isCookable() {
+		return true;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testRabbit() {
+		Rabbit rabbit = new Rabbit("Rabbit", 1.0);
+		System.out.println(rabbit.getName() == "Rabbit");
+		System.out.println(rabbit.getWeight() == 1.0);
+		System.out.println(rabbit.isCookable() == true);
+	}
+}
diff --git a/assignment3/Question1/Start.java b/assignment3/Question1/Start.java
new file mode 100644
index 0000000..6bf9d3b
--- /dev/null
+++ b/assignment3/Question1/Start.java
@@ -0,0 +1,10 @@
+public class Start {
+	public static void main(String[] args) {
+		Mammal.testMammal();
+		Human.testHuman();
+		Rabbit.testRabbit();
+		EuropeanRabbit.testEuropeanRabbit();
+		LapinSauteChasseur.testLapinSauteChasseur();
+		FrankTheRabbit.testFrankTheRabbit();
+	}
+}
diff --git a/assignment3/Question2/CastIronPot.java b/assignment3/Question2/CastIronPot.java
new file mode 100644
index 0000000..2f189cc
--- /dev/null
+++ b/assignment3/Question2/CastIronPot.java
@@ -0,0 +1,34 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Mammal class
+ */
+
+public class CastIronPot {
+	private Rabbit rabbit;
+
+	/**
+	 * Constructor.
+	 *
+	 * @param rabbit
+	 */
+	public CastIronPot(Rabbit rabbit) {
+		this.rabbit = rabbit;
+	}
+
+	/**
+	 * Getter.
+	 *
+	 * @return rabbit
+	 */
+	public Rabbit getRabbit() {
+		return rabbit;
+	}
+
+	public static void testCastIronPot() {
+		Rabbit lsc1 = new Rabbit("LSC1", 3.9);
+		CastIronPot cip = new CastIronPot(lsc1);
+		Rabbit lsc2 = cip.getRabbit();
+		System.out.println(lsc1 == lsc2);
+	}
+}
diff --git a/assignment3/Question2/EuropeanRabbit.java b/assignment3/Question2/EuropeanRabbit.java
new file mode 100644
index 0000000..540cb5c
--- /dev/null
+++ b/assignment3/Question2/EuropeanRabbit.java
@@ -0,0 +1,43 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: European rabbit
+ */
+
+public class EuropeanRabbit extends Rabbit {
+	/**
+	 * Constructor.
+	 *
+	 * @param name   The name of the Rabbit.
+	 * @param weight The weight of the Rabbit.
+	 */
+	public EuropeanRabbit(String name, double weight) {
+		super(name, weight);
+	}
+
+	/**
+	 * Constructor. With default weight 2.0
+	 *
+	 * @param name The name of the Rabbit.
+	 */
+	public EuropeanRabbit(String name) {
+		this(name, 2.0);
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testEuropeanRabbit() {
+		// test first constructor
+		Rabbit rabbit = new EuropeanRabbit("Bugs Bunny");
+		System.out.println(rabbit.getName() == "Bugs Bunny");
+		System.out.println(rabbit.getWeight() == 2.0);
+		System.out.println(rabbit.isCookable() == true);
+
+		// test second constructor
+		Rabbit rabbit2 = new EuropeanRabbit("Daffy Duck", 3.0);
+		System.out.println(rabbit2.getName() == "Daffy Duck");
+		System.out.println(rabbit2.getWeight() == 3.0);
+		System.out.println(rabbit2.isCookable() == true);
+	}
+}
diff --git a/assignment3/Question2/FrankTheRabbit.java b/assignment3/Question2/FrankTheRabbit.java
new file mode 100644
index 0000000..96c14fa
--- /dev/null
+++ b/assignment3/Question2/FrankTheRabbit.java
@@ -0,0 +1,36 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: European rabbit
+ */
+
+public class FrankTheRabbit extends Rabbit {
+	/**
+	 * Constructor.
+	 *
+	 * With name "Frank" and weight of 100.0
+	 */
+	public FrankTheRabbit() {
+		super("Frank", 100.0);
+	}
+
+	/**
+	 * Frank rabbit can not be cooked.
+	 *
+	 * @return false
+	 */
+	@Override
+	public boolean isCookable() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testFrankTheRabbit() {
+		FrankTheRabbit frank = new FrankTheRabbit();
+		System.out.println(frank.getName() == "Frank");
+		System.out.println(frank.getWeight() == 100.0);
+		System.out.println(frank.isCookable() == false);
+	}
+}
diff --git a/assignment3/Question2/Human.java b/assignment3/Question2/Human.java
new file mode 100644
index 0000000..e39286d
--- /dev/null
+++ b/assignment3/Question2/Human.java
@@ -0,0 +1,36 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Human class
+ */
+
+public class Human extends Mammal {
+
+	/**
+	 * Constructor.
+	 * 
+	 * The Constructor take no argument. All human are named "Alice"
+	 */
+	public Human() {
+		super("Alice");
+	}
+
+	/**
+	 * Human cannot be cooked.
+	 *
+	 * @return false
+	 */
+	@Override
+	public boolean isCookable() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testHuman() {
+		Human human = new Human();
+		System.out.println(human.getName() == "Alice");
+		System.out.println(human.isCookable() == false);
+	}
+}
diff --git a/assignment3/Question2/LapinSauteChasseur.java b/assignment3/Question2/LapinSauteChasseur.java
new file mode 100644
index 0000000..216f06a
--- /dev/null
+++ b/assignment3/Question2/LapinSauteChasseur.java
@@ -0,0 +1,26 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Lapin Saute Chasseur
+ */
+
+public class LapinSauteChasseur extends EuropeanRabbit {
+	/**
+	 * Constructor.
+	 *
+	 * With name "Delicious" and has a weight of 0.5
+	 */
+	public LapinSauteChasseur() {
+		super("Delicious", 0.5);
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testLapinSauteChasseur() {
+		LapinSauteChasseur rabbit = new LapinSauteChasseur();
+		System.out.println(rabbit.getName() == "Delicious");
+		System.out.println(rabbit.getWeight() == 0.5);
+		System.out.println(rabbit.isCookable() == true);
+	}
+}
diff --git a/assignment3/Question2/Mammal.java b/assignment3/Question2/Mammal.java
new file mode 100644
index 0000000..1f76242
--- /dev/null
+++ b/assignment3/Question2/Mammal.java
@@ -0,0 +1,53 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Mammal class
+ */
+
+public class Mammal {
+	/**
+	 * Name of the mammal
+	 */
+	private String name;
+
+	/**
+	 * Constructor
+	 * 
+	 * @param name
+	 *             name of the mammal
+	 */
+	public Mammal(String name) {
+		this.name = name;
+	}
+
+	/**
+	 * Get the name of the mammal
+	 * 
+	 * @return name of the mammal
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Whether the mammal is can be cooked.
+	 * Some mammals can be cooked and some mammals cannot be cooked so for safety
+	 * reason the isCookable method just prints a message "Do not cook this!" and
+	 * returns false.
+	 *
+	 * @return false
+	 */
+	public boolean isCookable() {
+		System.out.println("Do not cook this!");
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testMammal() {
+		Mammal mammal = new Mammal("Mammal 1");
+		System.out.println(mammal.getName() == "Mammal 1");
+		System.out.println(mammal.isCookable() == false);
+	}
+}
diff --git a/assignment3/Question2/Rabbit.java b/assignment3/Question2/Rabbit.java
new file mode 100644
index 0000000..c1d8063
--- /dev/null
+++ b/assignment3/Question2/Rabbit.java
@@ -0,0 +1,54 @@
+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-11
+ * Description: Rabbit class
+ */
+
+public class Rabbit extends Mammal {
+	/**
+	 * The weight of the rabbit.
+	 */
+	private double weight;
+
+	/**
+	 * Getter for the weight of the rabbit.
+	 *
+	 * @return the weight of the rabbit
+	 */
+	public double getWeight() {
+		return weight;
+	}
+
+	/**
+	 * Constructor.
+	 *
+	 * @param name
+	 * 	  the name of the rabbit
+	 * @param weight
+	 * 	  the weight of the rabbit
+	 */
+	public Rabbit(String name, double weight) {
+		super(name);
+		this.weight = weight;
+	}
+
+	/**
+	 * Rabbit can be cooked.
+	 *
+	 * return true
+	 */
+	@Override
+	public boolean isCookable() {
+		return true;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testRabbit() {
+		Rabbit rabbit = new Rabbit("Rabbit", 1.0);
+		System.out.println(rabbit.getName() == "Rabbit");
+		System.out.println(rabbit.getWeight() == 1.0);
+		System.out.println(rabbit.isCookable() == true);
+	}
+}
diff --git a/assignment3/Question2/Start.java b/assignment3/Question2/Start.java
new file mode 100644
index 0000000..3094561
--- /dev/null
+++ b/assignment3/Question2/Start.java
@@ -0,0 +1,11 @@
+public class Start {
+	public static void main(String[] args) {
+		Mammal.testMammal();
+		Human.testHuman();
+		Rabbit.testRabbit();
+		EuropeanRabbit.testEuropeanRabbit();
+		LapinSauteChasseur.testLapinSauteChasseur();
+		FrankTheRabbit.testFrankTheRabbit();
+		CastIronPot.testCastIronPot();
+	}
+}