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Answer and Explanation

Question 10

What output is produced by the program shown in Listing 10 ?

  • A. Compiler Error
  • B. Runtime Error
  • C. Base
  • D. A B
  • E. None of the above.
Listing 10 . Listing for Question 10.
public class Ap129{ public static void main(String args[]){new Worker().doIt(); }//end main()}//end class Ap129 class Worker{void doIt(){ Base myVar = new A();myVar.test(); myVar = new B();myVar.test(); System.out.println("");}//end doIt() }// end class Workerclass Base{ public void test(){System.out.print("Base ");}; }//end class Baseclass A extends Base{ public void test(){System.out.print("A "); }//end test()}//end class A class B extends Base{public void test(){ System.out.print("B ");}//end test() }//end class B

Answer and Explanation

Listings

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Miscellaneous

This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Ap0110: Self-assessment, Extending classes, overriding methods, and polymorphic behavior
  • File: Ap0110.htm
  • Originally published: 2002
  • Published at cnx.org: 12/08/12
  • Revised: 12/03/14
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Answers

Answer 10

D. A B

Explanation 10

Another illustration of simple polymorphic behavior

In this program, two classes named A and B extend the class named Base , each overriding the method named test to produce different behavior. (Typically, overridden methods in different classes will produce different behavior, even though they have the same names.)

Behavior appropriate for object on which method is called

Questions & Answers

Ayele, K., 2003. Introductory Economics, 3rd ed., Addis Ababa.
Widad Reply
can you send the book attached ?
Ariel
?
Ariel
What is economics
Widad Reply
the study of how humans make choices under conditions of scarcity
AI-Robot
U(x,y) = (x×y)1/2 find mu of x for y
Desalegn Reply
U(x,y) = (x×y)1/2 find mu of x for y
Desalegn
what is ecnomics
Jan Reply
this is the study of how the society manages it's scarce resources
Belonwu
what is macroeconomic
John Reply
macroeconomic is the branch of economics which studies actions, scale, activities and behaviour of the aggregate economy as a whole.
husaini
etc
husaini
difference between firm and industry
husaini Reply
what's the difference between a firm and an industry
Abdul
firm is the unit which transform inputs to output where as industry contain combination of firms with similar production 😅😅
Abdulraufu
Suppose the demand function that a firm faces shifted from Qd  120 3P to Qd  90  3P and the supply function has shifted from QS  20  2P to QS 10  2P . a) Find the effect of this change on price and quantity. b) Which of the changes in demand and supply is higher?
Toofiq Reply
explain standard reason why economic is a science
innocent Reply
factors influencing supply
Petrus Reply
what is economic.
Milan Reply
scares means__________________ends resources. unlimited
Jan
economics is a science that studies human behaviour as a relationship b/w ends and scares means which have alternative uses
Jan
calculate the profit maximizing for demand and supply
Zarshad Reply
Why qualify 28 supplies
Milan
what are explicit costs
Nomsa Reply
out-of-pocket costs for a firm, for example, payments for wages and salaries, rent, or materials
AI-Robot
concepts of supply in microeconomics
David Reply
economic overview notes
Amahle Reply
identify a demand and a supply curve
Salome Reply
i don't know
Parul
there's a difference
Aryan
Demand curve shows that how supply and others conditions affect on demand of a particular thing and what percent demand increase whith increase of supply of goods
Israr
Hi Sir please how do u calculate Cross elastic demand and income elastic demand?
Abari
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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