Consider the abstract superclass below:
public abstract class foo
{
private int a;
public int b;

public foo( int aval, int bval )
{
a = aval;
b = bval;
} // end foo constructor

public abstract int calculate();
} // end class foo

any concrete subclass that extends class foo:
1) must implement a method called calculate.
2) will not be able to access the instance variable a.
3) neither (a) nor (b).
4) both (a) and (b).

Ihave a music player on my phone. i can buy songs, add them to playlists and play them. obviously it would be redundant to store each song in each playlist; each playlist is just a list of pointers to the songs. for this lab you will simulate this behavior. your program will need to have options to: add songs to the system library (you will store the text of the first line of the song, rather than the audio) add playlists add songs to a playlist list playlists play a playlist list all of the songs in the library with a count of how many times each song has been played remove a song from a playlist remove a playlist remove a song from the library (and thus from all playlists that contain it) note that we will not be checking many error cases. in real programming this would be bad, you should usually try to recognize and respond to as many types of errors as you can. in the context of class we are trying to acquaint you with as many concepts as possible, so for the sake of educational efficiency we will not be checking most errors in this lab, you may assume that your user provides correct input. you may add all appropriate error testing if you wish, but we will not be testing for it.

What is outfitting a workplace with video in a technology

Kirk found a local community college with a two-year program and he is comparing the cost with that of an out-of-state two-year school. what is the expected total cost for one year at the local community college if kirk lives at home? what is the expected total cost for one year at the out-of-state school if kirk lives on campus?