Thread: Do While Loop

So I am prompting the user for donations in a do while loop while the total is less than 500. I need to print out who the highest donor was, how would I do this?

Yes I have thought about it, I have thought about passing the donation amount to another variable but when it loops up and around to repeat the code then wont the value stored in that variable be wiped?

1.
- A For Loop to ask the donor's for their donation details (name & amount)
- donationQuantity Variable to calculate amount of donations.
- maxDonation Variable to calculate the total of donations.
while (max donation is less than 500)
2.
- print number of donations
- print who donated the highest ***** (This is the one I am struggling on)

I have got everything working, it's just I am stuck on what else to add so that I can output 'who donated the most'. Im guessing this would require me to add something inside the loop to store each amount, I cant think how :?

Oh, with an IF Statement, I think I know now

I don't know the answer to this

I would do an if statement:

if(newDonation>currentDonation)
{
newdonation=highestdonation
}

Thanks for pointing that out, I need to change the values of highest donation not newDonation, therefore, I think the condition should be:
highestDonation=newDonation
I have not initialised currentDonation, therefore, it shows an error. I am maybe going the wrong way about this, I appreciate your help in leading me in the right direction.

I havent defined current, I don't know what to initialise it as,
The newDonation is defined under the prompt so that it will store what the user enters.

I thought id need it for the if statement,

Im not 100% sure, so i guess i dont need it.

Depending on the application of your program, ie practice vs daily, I would suggest using an array.

Check out the ArrayList type

I'd make a donation instance variable available to each object, then make an array as a list of those objects (maybe add it to the array through a constructor). Iterate through the array of objects who call to the donation instance variable.

If obj1.donation > obj2.donation
highestDonation = obj1

Until you've iterated all objects.

But I may be making it more difficult than it needs to be. I always prefer arrays.

I tried my method and it was a big whopping fail, haha.

I'm not sure why I thought creating an object for each person was a good idea, but I feel like just making a multidimensional array, or two separate array lists, would be a better plan.

One for the person, the other for their donation and make sure indices remain in alignment.

I'll post my goofball attempt shortly.

You have a few ways to do this, so start by breaking the problem into small steps. First, you have to get the values of the donations. If you have a lot of donations, it can be very time-consuming and impractical to create a new variable for each. One way around this would be to store each value in an array. Each value should have its own unique index, that is, one value shouldn't override another. Second, after all of them have been entered, you can create a loop that compares two values, stores the higher value under a different variable and keeps going until the array list is completely checked.

Alternatively, if you're not a fan of arrays, you can use 2 variables and constantly update their values. One variable would store the user's entered value, the other would store the higher of the two values. This approach is a bit tricky because at first, there is only 1 user entered value. You can either compare it with 0 or simply wait for a second value.

There are probably other ways to approach this problem but these are the first 2 that popped into my head. The type of loop (for, do-while or while) doesn't matter, although based on the title of the thread, I'm guessing you would use a do-while loop.

Third, you have to ensure the sum of the donations is less than 500 and work this into the loop(s).
Fourth, something has to happen when the sum is 500. There are many ways to approach this, some which can be done through a single primitive method, whereas others would take more work.

Each of those four steps have to be broken down further but I'll leave that part up to you.

I have been changing things, trying different things out based on what you guys have said, I am still having trouble. Here is my code

public class Donations
{
   public static void main(String[] args)
   {
      Scanner keyboard= new Scanner (System.in);
      String donorName;
      int newDonation, donationQuantity=0, maxDonation=0, highestDonation;
 
      do
      {
         System.out.println("\n");
         System.out.println("Please enter donation amount");        //PRINT
         newDonation=keyboard.nextInt();
 
         System.out.println("Please enter your name");              //PRINT
         donorName=keyboard.next();
 
         highestDonation=newDonation;
 
         if(newDonation>highestDonation)
         {
            highestDonation=newDonation;
         }
 
 
         donationQuantity=donationQuantity+1;
 
         maxDonation +=newDonation;
 
 
      }
      while (maxDonation<500);
 
      System.out.println("It took " + donationQuantity + " donations to reach the £500");
 
      System.out.println("Highest donor was " + highestDonation);

I know the initialisation of highestDonation is wrong, I don't know how to fix that.