ch8 done

ch8/Abstract.java

@@ -0,0 +1,38 @@
+//final abstract class lain{ // ERROR, can't be inherited
+//    void pain(){
+//        System.out.println("Big bang");
+//    }
+//    //final void pain(){ // you can't stop java from compiling errors
+//    //    System.out.println("Big bang");
+//    //}
+//}
+
+abstract class lain{
+    void pain(){
+        System.out.println("Big bang");
+    }
+    //final void pain(){ // you can't stop java from compiling errors
+    //    System.out.println("Big bang");
+    //}
+}
+
+
+class habeba extends lain{
+    void pain(){
+        System.out.println("habeba is the only queen and true warrior"); // gotta stop simping real hard
+    }
+}
+
+class Abstract {
+    static public void main(String[] args) {
+        lain lainObj = new habeba();
+        lainObj.pain();
+
+        habeba habObj = new habeba();
+        habObj.pain();
+
+        System.out.println("heeeeeeeey");
+        System.out.println(habObj.toString());
+        System.out.println(habObj.hashCode());
+    }
+}

ch8/Shapes.java

@@ -0,0 +1,57 @@
+class twoD{
+    private double width;
+    private double height;
+
+
+    double getWidth () {return width; }
+    double getHeight () {return height; }
+    void setW(double w) { width = w ;}
+    void setH(double h) { height = h ;}
+
+    twoD(){
+    }
+
+    twoD(double w,double h){
+        width = w;
+        height = h;
+    }
+
+    void showD(){
+        System.out.println("w: " + width + ", h: " + height);
+    }
+}
+
+class Triangle extends twoD{
+    String style;
+
+    Triangle( String s, double w, double h){
+        super(w,h);
+        style  = s;
+    }
+
+    double area(){
+        return getHeight() * getWidth();
+    }
+
+    void showStyle(){
+        System.out.println(style);
+    }
+}
+
+class ColorTriangle extends Triangle{
+    private String color;
+
+    ColorTriangle(String c, String s, double w, double h){
+        super(s,w,h);
+        color = c;
+    }
+}
+
+class Shapes{
+
+    twoD fsf = new twoD();
+
+    public static void main(String[] args){
+        System.out.println("hhhhh");
+    }
+}

ch8/hab.java

@@ -0,0 +1,32 @@
+class X{
+    int a;
+    X(int i) {a=i;}
+}
+
+class Y{
+    int a;
+    Y(int i ) {a=i;}
+}
+
+class Z extends X{
+    int b;
+    Z(int i, int j){
+        super(j);
+        b = i;
+    }
+}
+
+
+class  hab {
+    public static void main(String args[]){
+        X x = new X(10);
+        X x2;
+        Y y = new Y(5);
+        Z z;
+        x2 = x;
+        X x3;
+        x3 = new Z(4,4);
+        // z = new X(3); // should result in an error too
+        // x2 = y; // should result in a compilations error
+    }
+}

ch8/overriding.java

@@ -0,0 +1,75 @@
+class A{
+    int i,j;
+    A(int a, int b){
+        i=a;
+        j=b;
+    }
+    void show(){
+        System.out.println( i +  j);
+    }
+}
+
+class B extends A{
+    int k;
+    B(int a, int b, int c){
+        super(a, b);
+        k = c;
+    }
+    void show() {
+        System.out.println(k);
+    }
+}
+
+class Sup {
+    void who () {
+        System.out.println("who in sup");
+    }
+}
+
+class Sub1 extends Sup{
+    void who() {
+        System.out.println("sub1");
+    }
+}
+
+class Sub2 extends Sup{
+    void who() {
+        System.out.println("sub2");
+    }
+}
+
+class Exp {
+    void who(Sup i){
+        i.who();
+    }
+
+    void IfWho(Sup i){
+    }
+}
+
+class overriding{
+    public static void main(String[] args){
+        A a = new A(1,2);
+        a.show();
+        B b = new B(1,2,3);
+        b.show();
+
+        Sup SupRef;
+
+        Sup SupObj= new Sup();
+        Sub1 Sub1Obj = new Sub1();
+        Sub2 Sub2Obj = new Sub2();
+
+        SupRef = SupObj;
+        SupRef.who();
+
+        SupRef = Sub1Obj;
+        SupRef.who();
+
+        SupRef = Sub2Obj;
+        SupRef.who();
+
+        Exp ExpObj = new Exp();
+        ExpObj.who(SupObj);
+    }
+}