Wednesday, September 15, 2010

Chapter 2 test

/**

* Create rating for movie

*/

public class MovieRating

{

private String MovieName; //field

private int RunningTime;

private int numberOfRatings = 0;

private int averageRating = 0;

private int totalRating = 0; //declaration

private int maxRating = 0;

/**

* Constructor for objects of class MovieRating

*/

public MovieRating(String name, int time) //constuctor

{

MovieName = name; // local variable initialized

RunningTime = time;

}

/**

* return MovieName

*/

public void changeName (String newName) //method signature

{

MovieName = newName; //method body

}

/**

* Set the running time in minutes.

*/

public void setRunningTime (int newRunningTime) //mutator

{

RunningTime = newRunningTime;

}

/**

* Get the running time in minutes. //comment

*/

public int getRunningTime()

{

//RunningTime = RunningTime;

return RunningTime; //return statement

}

/**

* Rate movie from 1 to 10.

*/

public void addRating(int movieRating) //formal parameter (movieRating)

{

if (movieRating <> 10){ //conditional statement

System.out.println("Sorry. Only ratings of between 1 and 10 are accepted.");

System.out.println("");

return;

}

if (movieRating == 10){

maxRating = maxRating +1; // assignment statement

totalRating = totalRating + movieRating; //expression

numberOfRatings = numberOfRatings +1;

}

else {numberOfRatings = numberOfRatings +1;

totalRating = totalRating + movieRating; //"=" is an assignment operator

}

}

/**

* Print the movie rating.

*/

public void getaverageRating() // void return type

{

System.out.println(MovieName+" has an average rating of "+totalRating/numberOfRatings+" rated by "+numberOfRatings+ " people.");

}

/**

* Print the maximum rating.

*/

public void printMax() //accessor

{

System.out.println(MovieName + " has an average rating of "+averageRating+" rated by "+numberOfRatings+ " people. "+ maxRating+" person(s) gave the movie the maximum rating of 10.");

} //things inside these {} brackets are block statement.

}

3. For each of the 4 vocabulary items marked with an "o", write one meaningful sentence using that item in reference to an object of class MovieRating.

§ The actual parameter of a movieName is the name of the movie the use puts in. For example – Inception.

§ Instance variable are fields. For example - numberOfRatings, totalRating, MovieName, RunningTime etc.

§ Scope of a field is the whole class. Therefore, for example – scope of MovieName is the whole class.

§ For a local variable, its lifetime will last only until the method exists. Once the method is removed, it gets destroyed. However, for fields the lifetime exists forever. For example – RunningTime is a field and therefore it lasts until the instance exists. MovieName is a local variable and therefore its lifetimes is only until that method exists.

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