java program to add three numbers in java using inheritance..please help
class A { int a; int b; } class B extends A { int c; } class C extends B { int d; public int sum() { d=a+b+c; return d; } } class add { public static void main(String args[]) { A obj1= new A(); B obj2= new B(); C obj3= new C(); obj1.a = 1; obj1.b = 2; obj2.c = 3; System.out.println("sum is"+obj3.sum()); } } the output it showed was sum is 0 then i wrote again the code class A { int a; int b; void showab() { System.out.println(a+b); } } class B extends A { int c; void showc() { System.out.println(c); } } class C extends B { int d; public int sum() { d=a+b+c; return d; } } class add1 { public static void main(String args[]) { A obj1= new A(); B obj2= new B(); C obj3= new C(); obj1.a = 1; obj1.b = 2; obj1.showab(); obj2.c = 3; obj2.showc(); obj3.sum(); System.out.println("sum is"+obj3.sum()); } }output showed was 3,3 sum is 0
can anyone plz tell what mistake i made in my two programs and what basic i m lacking that garbage value i,e 0 comes again n again what methodology should i adopt to overcome this.