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Edited VirusStats to be end-of-line style, have more comments, and have a clearer loop structure
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‎out/production/c4t-java/com/codefortomorrow/beginner/chapter9/solutions/VirusStats.class

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‎src/com/codefortomorrow/beginner/chapter9/practice/VirusStats.java

Lines changed: 41 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -1,23 +1,47 @@
11
package com.codefortomorrow.beginner.chapter9.practice;
22

33
/*
4-
In this assignment, you will be required to
5-
have 5 different categories of information
6-
regarding a single topic that include
7-
String, int, and double array types.
8-
The arrays for the program should have 5 elements each.
9-
The program should prestore the information.
10-
However, the program should allow a Scanner to
11-
access information of user choice.
12-
You may store the information to the arrays
13-
however you see fit, but once it is stored
14-
a user should be able to ask for a specific
15-
stat for your set of data.
16-
The program should loop until the user enters “quit.
17-
Once the user types quit, the program should end.
18-
You are able to use any notes or previous programs
19-
to help aid you in creating this assignment.
20-
*/
4+
* Create a program called VirusStats
5+
* which takes user input for a country
6+
* and type of statistic and displays the
7+
* statistic asked for. The program should
8+
* end whenever the user enters "quit".
9+
*
10+
* Use separate 1D arrays for the type of stats,
11+
* countries, capitals, population, number of cases,
12+
* deaths, recoveries, death rates, recovery rates,
13+
* infection rates, and "risk grade." (Please note that
14+
* "risk grades" are not based on actual scientific
15+
* fact and were made up for the purposes of this exercise.)
16+
*
17+
* The data you need can be found here:
18+
* https://docs.google.com/spreadsheets/d/1XZ0GjALsu2mhraGMJoj37jTmy_S2sw51FFMeywqkcnw/edit?usp=sharing
19+
*
20+
* To calculate the death rate:
21+
* Take that country's deaths and divide it by the number of cases.
22+
*
23+
* To calculate the recovery rate:
24+
* Take that country's number of recoveries and divide it
25+
* by the number of cases.
26+
*
27+
* To calculate the infection rate:
28+
* Take that country's number of cases and divide it
29+
* by the population.
30+
*
31+
* For the rates: Bonus points if you can round them (or format them)
32+
* to the nearest hundredths place.
33+
*
34+
* To determine the "risk grade", where 'A' is most dangerous
35+
* and 'F' is least dangerous:
36+
*
37+
* 'A' if infection rate > 0.25 OR death rate > 25
38+
* 'B' if infection rate > 0.2 OR death rate > 15
39+
* 'C' if infection rate > 0.15 OR death rate > 10
40+
* 'D' if infection rate > 0.1 OR death rate > 5
41+
* 'F' for all else
42+
*
43+
* Sample output: https://youtu.be/rFuGY2wXcKc
44+
*/
2145

2246
public class VirusStats {
2347
public static void main(String[] args) {

‎src/com/codefortomorrow/beginner/chapter9/solutions/VirusStats.java

Lines changed: 165 additions & 115 deletions
Original file line numberDiff line numberDiff line change
@@ -1,20 +1,58 @@
11
package com.codefortomorrow.beginner.chapter9.solutions;
22

3-
import java.util.Scanner;
3+
/*
4+
* Create a program called VirusStats
5+
* which takes user input for a country
6+
* and type of statistic and displays the
7+
* statistic asked for. The program should
8+
* end whenever the user enters "quit".
9+
*
10+
* Use separate 1D arrays for the type of stats,
11+
* countries, capitals, population, number of cases,
12+
* deaths, recoveries, death rates, recovery rates,
13+
* infection rates, and "risk grade." (Please note that
14+
* "risk grades" are not based on actual scientific
15+
* fact and were made up for the purposes of this exercise.)
16+
*
17+
* The data you need can be found here:
18+
* https://docs.google.com/spreadsheets/d/1XZ0GjALsu2mhraGMJoj37jTmy_S2sw51FFMeywqkcnw/edit?usp=sharing
19+
*
20+
* To calculate the death rate:
21+
* Take that country's deaths and divide it by the number of cases.
22+
*
23+
* To calculate the recovery rate:
24+
* Take that country's number of recoveries and divide it
25+
* by the number of cases.
26+
*
27+
* To calculate the infection rate:
28+
* Take that country's number of cases and divide it
29+
* by the population.
30+
*
31+
* For the rates: Bonus points if you can round them (or format them)
32+
* to the nearest hundredths place.
33+
*
34+
* To determine the "risk grade", where 'A' is most dangerous
35+
* and 'F' is least dangerous:
36+
*
37+
* 'A' if infection rate > 0.25 OR death rate > 25
38+
* 'B' if infection rate > 0.2 OR death rate > 15
39+
* 'C' if infection rate > 0.15 OR death rate > 10
40+
* 'D' if infection rate > 0.1 OR death rate > 5
41+
* 'F' for all else
42+
*
43+
* Sample output: https://youtu.be/rFuGY2wXcKc
44+
*/
445

5-
public class VirusStats
6-
{
46+
import java.util.Scanner;
747

8-
public static void main(String[] args)
9-
{
10-
// Case, death, and recovery numbers are those reported by John Hopkins University at 2:01 PM on Wednesday 4/22/2020
11-
// Population is as reported by worldometers.info at 2:01 PM on 4/22/2020
12-
// Death rate, recovery rate, and infection rate are calculated using above data.
13-
// Alveera's Risk Letter Grade is self determined and is a fun educated guess not actual scientific fact
48+
public class VirusStats {
49+
public static void main(String[] args) {
50+
// types of statistics
51+
String[] stats = {"capital", "number of cases", "population", "deaths", "recoveries", "death rate", "recovery rate", "infection rate", "risk grade"};
1452

1553
// Data for 10 countries on COVID-19
1654
String[] countries = {"United States", "Spain", "Italy", "France", "Germany", "United Kingdom", "Turkey", "Iran", "China", "Russia"};
17-
String[] capitals = {"Washington D.C.", "Spain", "Rome", "Paris", "Berlin", "London", "Ankara", "Tehran", "Beijing", "Moscow"};
55+
String[] capitals = {"Washington D.C.", "Madrid", "Rome", "Paris", "Berlin", "London", "Ankara", "Tehran", "Beijing", "Moscow"};
1856
int[] population = {331002651, 46754778, 60461826, 65273511, 83783942, 67886011, 84339067, 83992949, 1439323776, 145934462};
1957
int[] numberOfCases = {826248, 208389, 183957, 159315, 149044, 134635, 95591, 85996, 83868, 57999};
2058
int[] deaths = {45894, 21717, 25085, 20829, 5165, 18151, 2376, 5391, 4636, 513};
@@ -27,138 +65,150 @@ public static void main(String[] args)
2765

2866
// calculate death rate, recovery rate,
2967
// and infection rate for all countries
30-
for (int i = 0; i < countries.length; i++)
31-
{
68+
for (int i = 0; i < countries.length; i++) {
69+
// convert rates to a percent, and round to the nearest hundredth
3270
deathRate[i] = Math.round(deaths[i] / (double) numberOfCases[i] * 10000) / 100.0;
3371
recoveryRate[i] = Math.round(recoveries[i] / (double) numberOfCases[i] * 10000) / 100.0;
3472
infectionRate[i] = Math.round(numberOfCases[i] / (double) population[i] * 10000) / 100.0;
3573
}
3674

37-
// Determining Risk Grade
38-
for (int x = 0; x < countries.length; x++)
39-
{
40-
if (infectionRate[x] > 0.25 || deathRate[x] > 25)
41-
{
75+
// determine risk grade
76+
for (int x = 0; x < countries.length; x++) {
77+
if (infectionRate[x] > 0.25 || deathRate[x] > 25) {
4278
riskGrade[x] = 'A';
43-
}
44-
else if (infectionRate[x] > 0.2 || deathRate[x] > 15)
45-
{
79+
} else if (infectionRate[x] > 0.2 || deathRate[x] > 15) {
4680
riskGrade[x] = 'B';
47-
}
48-
else if (infectionRate[x] > 0.15 || deathRate[x] > 10)
49-
{
81+
} else if (infectionRate[x] > 0.15 || deathRate[x] > 10) {
5082
riskGrade[x] = 'C';
51-
}
52-
else if (infectionRate[x] > 0.1 || deathRate[x] > 5)
53-
{
83+
} else if (infectionRate[x] > 0.1 || deathRate[x] > 5) {
5484
riskGrade[x] = 'D';
55-
}
56-
else
57-
{
85+
} else {
5886
riskGrade[x] = 'F';
5987
}
6088
}
6189

62-
// Printing out instructions
90+
// Print out user instructions
6391
System.out.println("The following countries have been stored in our database:");
64-
System.out.println("[United States, Spain, Italy, France, Germany, United Kingdom, Turkey, Iran, China, Russia]\n");
92+
93+
// print countries in the countries array
94+
System.out.print("[");
95+
for (int i = 0; i < countries.length; i++) {
96+
System.out.print(countries[i]);
97+
if (i < countries.length - 1) {
98+
System.out.print(", ");
99+
} else {
100+
System.out.println("]");
101+
}
102+
}
103+
104+
System.out.println();
105+
106+
// print stat types
65107
System.out.println("The following stats are available for selection:");
66-
System.out.println("[Capital, Number of Cases, Population, Deaths, Recoveries, Death Rate, Recovery Rate, Infection Rate, Risk Grade]");
108+
System.out.print("[");
109+
for (int i = 0; i < stats.length; i++) {
110+
System.out.print(stats[i]);
111+
if (i < stats.length - 1) {
112+
System.out.print(", ");
113+
} else {
114+
System.out.println("]");
115+
}
116+
}
117+
67118
System.out.println("\t**Risk Grade is a rating of how dangerous the virus is in that country, A being most dangerous and F being least dangerous.\n");
68119
System.out.println("Type \"quit\" to end the program.\n");
69120

70-
String country = "";
71-
String stat;
72-
int index = -1;
121+
String country; // name of the country the user is researching
122+
String stat; // type of statistic the user wants
123+
int index = -1; // index of the country
73124

74125
Scanner reader = new Scanner(System.in);
75-
76-
// Enter a country
77-
while (!country.equalsIgnoreCase("quit"))
78-
{
79-
while (index == -1)
80-
{
81-
System.out.print("Which country’s stats would you like to research? ");
82-
country = reader.nextLine();
83-
// Break While
84-
if (country.equalsIgnoreCase("quit"))
85-
{
86-
index = -2;
87-
}
88-
// Finds index
89-
for (int x = 0; x < countries.length; x++)
90-
{
91-
if (countries[x].equalsIgnoreCase(country))
92-
{
93-
index = x;
126+
127+
boolean quit = false; // whether the user wants to quit
128+
do {
129+
// keep asking the user for a country until
130+
// they give a valid country
131+
while (index == -1) {
132+
System.out.print("Which country's stats would you like to research? ");
133+
country = reader.nextLine().toLowerCase(); // case insensitive
134+
135+
// if user quits, exit the program
136+
if (country.equals("quit")) {
137+
System.out.println("Quitting...");
138+
quit = true;
139+
break;
140+
} else { // user enters a country
141+
// find the index of that country
142+
for (int i = 0; i < countries.length; i++) {
143+
if (country.equalsIgnoreCase(countries[i])) { // case insensitive
144+
index = i; // match found
145+
}
146+
}
147+
148+
// if the country given is invalid
149+
if (index == -1) {
150+
// print error message
151+
System.out.println("Sorry, we don't have data for that country. Please try again.");
94152
}
95-
}
96-
// Invalid Response
97-
if (index == -1)
98-
{
99-
System.out.println("This response was invalid; try again.");
100153
}
101154
}
102-
103-
// QUIT GAME
104-
if (country.equalsIgnoreCase("quit"))
105-
{
106-
break;
107-
}
108-
109-
// Instructions
110-
System.out.print("Which stat would you like? ");
111-
stat = reader.nextLine();
112-
System.out.println();
113-
114-
// Bring stat
115-
if (stat.equalsIgnoreCase("capital"))
116-
{
117-
System.out.println(countries[index] + "'s capital is " + capitals[index] + ".");
118-
}
119-
else if (stat.equalsIgnoreCase("number of cases"))
120-
{
121-
System.out.println(countries[index] + " has " + numberOfCases[index] + " cases of COVID-19.");
122-
}
123-
else if (stat.equalsIgnoreCase("population"))
124-
{
125-
System.out.println(countries[index] + " has a population of " + population[index] + " people.");
126-
}
127-
else if (stat.equalsIgnoreCase("deaths"))
128-
{
129-
System.out.println(countries[index] + " has " + deaths[index] + " coronavirus related deaths.");
130-
}
131-
else if (stat.equalsIgnoreCase("recoveries"))
132-
{
133-
System.out.println(countries[index] + " has " + recoveries[index] + " people who recovered from COVID-19.");
134-
}
135-
else if (stat.equalsIgnoreCase("death rate"))
136-
{
137-
System.out.println(countries[index] + " has a " + deathRate[index] + "% coronavirus death rate.");
138-
}
139-
else if (stat.equalsIgnoreCase("recovery rate"))
140-
{
141-
System.out.println(countries[index] + " has a " + recoveryRate[index] + "% coronavirus recovery rate.");
142-
}
143-
else if (stat.equalsIgnoreCase("infection rate"))
144-
{
145-
System.out.println(countries[index] + " has a " + infectionRate[index] + "% COVID-19 infection rate.");
146-
}
147-
else if (stat.equalsIgnoreCase("risk grade"))
148-
{
149-
System.out.println(countries[index] + " has a risk grade of " + riskGrade[index] + ".");
150-
}
151-
else
152-
{
153-
System.out.println("This response was invalid; try again.");
155+
156+
if (!quit) {
157+
boolean validStatistic = false; // whether the user has entered a valid stat type
158+
159+
// keep asking user for a stat type until they give a valid stat type or quit the program
160+
while (!validStatistic) {
161+
System.out.print("Which stat would you like? ");
162+
stat = reader.nextLine().toLowerCase(); // case insensitive
163+
validStatistic = true; // assume stat type is valid
164+
165+
// bring up the stat the user wants
166+
switch (stat) {
167+
case "capital":
168+
System.out.println(countries[index] + "'s capital is " + capitals[index] + ".");
169+
break;
170+
case "number of cases":
171+
System.out.println(countries[index] + " has " + numberOfCases[index] + " cases of COVID-19.");
172+
break;
173+
case "population":
174+
System.out.println(countries[index] + " has a population of " + population[index] + " people.");
175+
break;
176+
case "deaths":
177+
System.out.println(countries[index] + " has " + deaths[index] + " COVID-19 related deaths.");
178+
break;
179+
case "recoveries":
180+
System.out.println(countries[index] + " has " + recoveries[index] + " people who recovered from COVID-19.");
181+
break;
182+
case "death rate":
183+
System.out.println(countries[index] + " has a " + deathRate[index] + "% COVID-19 death rate.");
184+
break;
185+
case "recovery rate":
186+
System.out.println(countries[index] + " has a " + recoveryRate[index] + "% COVID-19 recovery rate.");
187+
break;
188+
case "infection rate":
189+
System.out.println(countries[index] + " has a " + infectionRate[index] + "% COVID-19 infection rate.");
190+
break;
191+
case "risk grade":
192+
System.out.println(countries[index] + " has a risk grade of " + riskGrade[index] + ".");
193+
break;
194+
case "quit":
195+
System.out.println("Quitting...");
196+
quit = true;
197+
break;
198+
default: // invalid stat type
199+
System.out.println("Sorry, we don't have that stat. Please try again.");
200+
validStatistic = false;
201+
}
202+
}
154203
}
155-
// todo if you enter quit after asking "Which stat would you like?" it doesn't quit immediately
156204

157-
// Prepare for loop
205+
// reset index (next iteration will ask user for country again)
158206
index = -1;
159207
System.out.println();
160-
System.out.println();
161-
}
208+
} while (!quit);
209+
210+
System.out.println("You have successfully exited the program.");
211+
162212
reader.close();
163213
}
164214
}

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