Before this the user inputs an int for numOfTimes. Say it's 5. This will ask the question 5 times. But each time through it will erase the previous value in hrs1. It needs to be a separate variable. So if numOfTimes=5 Then I should get 5 different doubles for "Hour " and 5 different doubles for "Minute ". (assuming the user inputs different times) but they all need to be stored in different variables. How should I do this?
Thank you my question has been answered!
use an array ..
int a[] = new int[5];
for(int i =0;i<5;i++){
a[i] = //your value
}
You just need to put your "calculate average" code outside the for loop. I am not sure exactly how you want to calculate the average. But here are two simple ways.
Method one - keep track of the totals and calculate the basic average.
public class AvgTime {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("How many times? ");
int numOfTimes = in.nextInt();
System.out.println("\n");
double hrTotal = 0;
double minTotal = 0;
for (int i = 1; i <= numOfTimes; i++){
System.out.println("What Time (military time): ");
System.out.print("Hour ");
double hrs1 = in.nextDouble();
System.out.print("Minute ");
double min1 = in.nextDouble();
hrTotal += hrs1;
minTotal += min1;
}
//calculate average
double avdHr1 = hrTotal/numOfTimes;
double timeMin1 = minTotal/numOfTimes;
System.out.println(avgHr1+":"+timeMin1 + " P.M");
}
}
Method 2 - Use lists and iterate twice
public class AvgTime {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("How many times? ");
int numOfTimes = in.nextInt();
System.out.println("\n");
ArrayList<Double> hours = new ArrayList<>();
ArrayList<Double> minutes = new ArrayList<>();
double minTotal = 0;
for (int i = 1; i <= numOfTimes; i++){
System.out.println("What Time (military time): ");
System.out.print("Hour ");
double hrs1 = in.nextDouble();
System.out.print("Minute ");
double min1 = in.nextDouble();
hours.add(hrs1);
minutes.add(min1);
}
//calculate average
double avgHr1 = 0;
double timeMin1 = 0:
for (int i = 0; i < hours.size(); i++) {
double hour = hours.get(i);
double minute = minutes.get(i);
//ToDo: calculate average so far
}
System.out.println(avgHr1+":"+timeMin1 + " P.M");
}
You can use arrays to store the information the user has input. Before the loop, make an array using the new keyword, e.g. double[] hrs=new double[numOfTimes]. In the loop, write to different locations in the array for each input, hrs[i]=in.nextDouble(). You can later read from a position on the array using the syntax 'name[index]', such as 'hrs[2]'. Note that for java and many other languages, arrays start at 0. This means for an array [1,2,3] named arr, arr[1] equals 2 instead of 1. This means it would be best if your for loop was changed from for(int i=1;i<=numofTimes;i++) to 'for(int i=0;i
<SOAPBOX,RANT,HIGHHORSE>
This is more of a code review than a straight answer, but something has been bugging me about newbie questions that I've observed on stackoverrflow.
When developing, I avoid keyboard input like the plague. It is such drudgery, especially with a loop such as in this program. So many newbie questions have user-keyboard input. Why?! It makes development so much more difficult!
I've rewritten your program to add the ability for testing data, completely avoiding the need for user-input during development. When testing is over, just switch the test/live comments around.
I'm sure there's a more elegant way, but this style has worked well for me, and I recommend it.
</SOAPBOX,RANT,HIGHHORSE>
import java.util.*;
import static java.lang.Math.abs;
public class AverageTimeWTestingData {
public static void main(String[] args) {
HourMin24[] ahm = null;
//EXACTLY ONE of the following lines must be commented out
//Test only:
ahm = getTestData();
//Live only:
// ahm = getDataFromUserInput();
double dTotalHours = 0.0;
for (HourMin24 hm : ahm){
System.out.println("Time: " + hm.iHour + ":" + hm.iMin);
dTotalHours += hm.iHour + (hm.iMin / 60);
}
System.out.println("Average time (" + ahm.length + "): " + (dTotalHours / ahm.length));
}
private static final HourMin24[] getDataFromUserInput() {
Scanner in = new Scanner(System.in);
System.out.print("How many times? ");
int numOfTimes = in.nextInt();
ArrayList<HourMin24> al24 = new ArrayList<HourMin24>(numOfTimes);
while(numOfTimes < 0) {
System.out.println("What Time (military time): ");
System.out.print("Hour ");
int iHour = in.nextInt();
System.out.print("Minute ");
int iMin = in.nextInt();
al24.add(new HourMin24(iHour, iMin));
numOfTimes--;
}
return al24.toArray(new HourMin24[al24.size()]);
}
private static final HourMin24[] getTestData() {
System.out.println("TEST MODE ON");
return new HourMin24[] {
new HourMin24(13, 1),
new HourMin24(23, 19),
new HourMin24(0, 59),
new HourMin24(16, 16),
};
}
}
class HourMin24 {
public int iHour;
public int iMin;
public HourMin24(int i_hour, int i_min) {
iHour = i_hour;
iMin = i_min;
}
}
Output:
[C:\java_code\]java AverageTimeWTestingData
TEST MODE ON
Time: 13:1
Time: 23:19
Time: 0:59
Time: 16:16
Average time (4): 13.0
