/** * An app for a mobile device * * Modifications: * CT: Added validation to se

Question

/**
* An app for a mobile device
*
* Modifications:
* CT: Added validation to setPrice
*
*
* @author
* @version 2018.04.30
*

public class App
{
private String name;
private String author;
private double price;
private int rating; // valid ratings are 1-4 or 0 meaning not rated
  
/**
* Create an app with the given name, author, price, and rating
* @param appName the app name
* @param appAuthor the app author
* @param appPrice the price of the app (0 if the app is free)
* @param appRating the app's rating
*/
public App(String appName, String appAuthor, double appPrice, int appRating)
{
name = appName;
author = appAuthor;
price = appPrice;
// TODO: ----------------- 1 -------------------
// TODO: Replace the statement below with a call to setRating that has the same effect
rating = appRating;
// TODO: ----------------- 1b -------------------
// TODO: Answer this question in a comment right below (no code for this one)
// TODO: (Tip: Update setRating based on TODO #3 below before answering.)
// Question: Why do you think we want to replace the assignment statement with a call to setRating?
// Your Answer:
}
  
/**
* Create an app with the given name, author, and price that is not rated
* @param appName the app name
* @param appAuthor the app author
* @param appPrice the price of the app (0 if the app is free)
*/
public App(String appName, String appAuthor, double appPrice)
{
name = appName;
author = appAuthor;
price = appPrice;
rating = 0;
}

/**
* @return the app name
*/
public String getName()
{
return name;
}
  
/**
* @return the app author
*/
public String getAuthor()
{
return author;
}
  
/**
* @return the app price
*/
public double getPrice()
{
return price;
}
  
/**
* Set the price of this app to the value given
* @param newPrice new price for this app
*/
public void setPrice(double newPrice)
{
if (newPrice >= 0) {
price = newPrice;
}
else {
System.out.println("Error: Price must be greater than or equal to 0");
}
}
  
/**
* @return true if this app is free, false otherwise
*/
public boolean isFree()
{
// TODO: ----------------- 2 -------------------
// TODO: Implement this method so that it behaves as specified.
// TODO: (If an app's price is 0, that means it is free.)
return false;
}
  
/**
* @return the app rating
*/
public int getRating()
{
return rating;
}
  
/**
* Set the rating of this app to the value given
* @param newRating new rating for this app
*/
public void setRating(int newRating)
{
// TODO: ----------------- 3 -------------------
// TODO: Add validation: The new rating must be in the range 1 - 4 (inclusive)
// TODO: If it's not, print an error message stating the valid range and don't update the rating
rating = newRating;
}
  
/**
* Reset the rating of this app to not rated
*/
public void resetRating()
{
rating = 0;
}
  
/**
* Increase the rating of this app by 1
*/
public void increaseRating()
{
// TODO: ----------------- 4 -------------------
// TODO: Update so that the rating is not allowed to go higher than 4.
// TODO: I.e., if the rating is already at 4, calling this method has no effect.
// TODO: Do not print anything in this method.
rating = rating + 1;
}

/**
* Decrease the rating of this app by 1
*/
public void decreaseRating()
{
// TODO: ----------------- 5 -------------------
// TODO: Update so that the rating is not allowed to go lower than 1.
// TODO: If the rating is already at 1, calling this method has no effect.
// TODO: If the rating is 0, calling this method has no effect.
// TODO: Do not print anything in this method.
rating = rating - 1;
}

/**
* Print information on this app
*/
public void printAppInfo()
{
System.out.println("---------------------------------");
System.out.println("App: " + name);
System.out.println("Author: " + author);
System.out.println("Price: $" + price);
System.out.println("Rating: " + rating);
// TODO: ----------------- 6 -------------------
// TODO: Update the two statements above:
// TODO: If an app is free it should print "Price: FREE" instead of "Price: $0"
// TODO: If an app is not rated yet (rating 0), it should print "Rating: (not rated)"
// TOCO: instead of "Rating: 0"
System.out.println("---------------------------------");
}
}

Explanation / Answer

* Modifications: * CT: Added validation to setPrice * * @author * @version 2018.04.30 */ public class App { private String name; private String author; private double price; private int rating; // valid ratings are 1-4 or 0 meaning not rated /** * Create an app with the given name, author, price, and rating * * @param appName the app name * @param appAuthor the app author * @param appPrice the price of the app (0 if the app is free) * @param appRating the app's rating */ public App(String appName, String appAuthor, double appPrice, int appRating) { name = appName; author = appAuthor; price = appPrice; // TODO: ----------------- 1 ------------------- // TODO: Replace the statement below with a call to setRating that has the same effect setRating(appRating); // TODO: ----------------- 1b ------------------- // TODO: Answer this question in a comment right below (no code for this one) // TODO: (Tip: Update setRating based on TODO #3 below before answering.) // Question: Why do you think we want to replace the assignment statement with a call to setRating? // Your Answer: to add validation for app rating } /** * Create an app with the given name, author, and price that is not rated * * @param appName the app name * @param appAuthor the app author * @param appPrice the price of the app (0 if the app is free) */ public App(String appName, String appAuthor, double appPrice) { name = appName; author = appAuthor; price = appPrice; rating = 0; } /** * @return the app name */ public String getName() { return name; } /** * @return the app author */ public String getAuthor() { return author; } /** * @return the app price */ public double getPrice() { return price; } /** * Set the price of this app to the value given * * @param newPrice new price for this app */ public void setPrice(double newPrice) { if (newPrice >= 0) { price = newPrice; } else { System.out.println("Error: Price must be greater than or equal to 0"); } } /** * @return true if this app is free, false otherwise */ public boolean isFree() { // TODO: ----------------- 2 ------------------- // TODO: Implement this method so that it behaves as specified. // TODO: (If an app's price is 0, that means it is free.) return price == 0; } /** * @return the app rating */ public int getRating() { return rating; } /** * Set the rating of this app to the value given * * @param newRating new rating for this app */ public void setRating(int newRating) { // TODO: ----------------- 3 ------------------- // TODO: Add validation: The new rating must be in the range 1 - 4 (inclusive) // TODO: If it's not, print an error message stating the valid range and don't update the rating if(rating < 1 || rating > 4) { System.out.println("Error. rating should be in the range 1 - 4 (inclusive)"); } else { rating = newRating; } } /** * Reset the rating of this app to not rated */ public void resetRating() { rating = 0; } /** * Increase the rating of this app by 1 */ public void increaseRating() { // TODO: ----------------- 4 ------------------- // TODO: Update so that the rating is not allowed to go higher than 4. // TODO: I.e., if the rating is already at 4, calling this method has no effect. // TODO: Do not print anything in this method. if(rating < 4) { rating = rating + 1; } } /** * Decrease the rating of this app by 1 */ public void decreaseRating() { // TODO: ----------------- 5 ------------------- // TODO: Update so that the rating is not allowed to go lower than 1. // TODO: If the rating is already at 1, calling this method has no effect. // TODO: If the rating is 0, calling this method has no effect. // TODO: Do not print anything in this method. if(rating > 1) { rating = rating - 1; } } /** * Print information on this app */ public void printAppInfo() { System.out.println("---------------------------------"); System.out.println("App: " + name); System.out.println("Author: " + author); if(isFree()) { System.out.println("FREE"); } else { System.out.println("Price: $" + price); } if(rating == 0) { System.out.println("Rating: (not rated)"); } else { System.out.println("Rating: " + rating); } // TODO: ----------------- 6 ------------------- // TODO: Update the two statements above: // TODO: If an app is free it should print "Price: FREE" instead of "Price: $0" // TODO: If an app is not rated yet (rating 0), it should print "Rating: (not rated)" // TOCO: instead of "Rating: 0" System.out.println("---------------------------------"); } }

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