Close: #1 Lab 7

lab/lab7/Question2/Animal.java

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+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/04/03
+ * Description: This is the abstract animal class.
+ */
+
+public abstract class Animal {
+	/**
+	 * The name for the animal.
+	 */
+	private String name;
+
+	/**
+	 * Constructor
+	 *
+	 * @param String. The name for the animal.
+	 */
+	public Animal(String name) {
+		this.name = name;
+	}
+
+	/**
+	 * Getter for the name.
+	 *
+	 * @return String. The name of the animal.
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Abstract getLegs methods returns as result the animal's number of legs.
+	 *
+	 * @return int. The number of legs.
+	 */
+	public abstract int getLegs();
+
+	/**
+	 * Abstract canFly methods returns as result the animal's ability to fly.
+	 *
+	 * @return boolean. The ability to fly.
+	 */
+	public abstract boolean canFly();
+
+	/**
+	 * Test.
+	 */
+	public static void testAnimal() {
+		Animal a = new Animal("Animal") {
+			@Override
+			public int getLegs() {
+				return 4;
+			}
+
+			@Override
+			public boolean canFly() {
+				return false;
+			}
+		};
+		System.out.println(a.getName() == "Animal");
+		System.out.println(a.getLegs() == 4);
+		System.out.println(a.canFly() == false);
+	}
+}

lab/lab7/Question2/Dog.java

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+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022/04/03
+ * Description: This is the class of Dog. Dog has 4 legs and can not fly.
+ */
+
+public class Dog extends Animal {
+	/**
+	 * Constructor of Dog.
+	 *
+	 * @param name String
+	 */
+	public Dog(String name) {
+		super(name);
+	}
+
+	/**
+	 * Dog has 4 legs.
+	 *
+	 * @return int
+	 */
+	@Override
+	public int getLegs() {
+		return 4;
+	}
+
+	/**
+	 * Dog can not fly.
+	 *
+	 * @return boolean
+	 */
+	@Override
+	public boolean canFly() {
+		return false;
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testDog() {
+		Dog d = new Dog("Jack");
+		System.out.println(d.getName() == "Jack");
+		System.out.println(d.getLegs() == 4);
+		System.out.println(d.canFly() == false);
+	}
+}
+

lab/lab7/Question2/Start.java

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+/**
+ * Answer to Question.
+ *
+ * Answer to Question 1:
+ *
+ * - Q: Should the getLegs methods be abstract? Why or why not?
+ *
+ * - A: Yes. Because different animal have different number of legs. In animal
+ * class we didn't define how many legs an animal has.
+ *
+ * - Q: Should the canFly methods be abstract? Why or why not?
+ *
+ * - A: Yes. Because different animal have different ability to fly. In animal
+ * class we didn't define how an animal can fly.
+ *
+ * - Q: Should the Animal class be abstract? Why or why not?
+ *
+ * - A: Yes. Because different animal have different properties. In animal class
+ * we didn't define how an animal is.
+ *
+ * - Q: What kinds of test can you write inside the testAnimal method?
+ *
+ * - A: You can write test for the getLegs and canFly methods. Before that, you
+ * need to inherit the Animal class and override the getLegs and canFly methods.
+ * Because the Animal class is abstract, you can't create an object of it.
+ */
+public class Start {
+	public static void main(String[] args) {
+		Animal.testAnimal();
+		Dog.testDog();
+	}
+}