Changing total value using the lowest amount of coins, whilst excluding a specific coin, and return result as String

I am facing an issue with one of my assignments, where a small part of the assignment is writing method for the below description:

> A method that takes two values; the value to exchange, and the coin type to exclude, and then return the minimum coins needed to exchange the for the total value, and return the output as a String. For example changeCalculator (555,50) may return "the coins to exchange are : 2 x 200p, 1 x 100p, 0x50, 2 x 20p, 1 x 10p, with a remainder of 5p".

I was able to write up a code, but the code I have written has System.out.print in the loop, and I am unable to make the code work whilst returning a string type, as I am using a loop.

All you need to know for my code, is at the start of the code class I have put and have already initialized the list of coins in the constructor:

private List<Integer> coinList = new ArrayList<Integer>();

Here is my code below:

public void changeCalaculator (int totalCoinValue, int excludedCoinType)
{
	System.out.print("The coins exchanged are: ");
	for (int coin : coinList)
	{
		if (excludedCoinType == coin)
		{
			continue;
		}
		else
		{

		System.out.print(totalCoinValue/coin + " x " + coin + "p, ");		
		totalCoinValue = totalCoinValue%coin;
		}	
	} 
	System.out.print(" with a reminader of " + totalCoinValue + "p"); 
}

• For your method to return a String you firstly need to change your method declaration to show that the method actually does have a return type.
• Furthermore, instead of printing out the results, just build up a String along the way and return it after your method is finished. In the following example I used a StringBuilder for this task.
• Lastly, you were missing the output from the branch when your excluded coin type is added. (You don't need the continue; here, because there is nothing else to do in the loop, once the if branch is true)

Updated example:

public String multiCoinCalulator(int totalCoinValue, int excludedCoinType) {
    StringBuilder sb = new StringBuilder();
    sb.append("The coins exchanged are: ");
    for (int coin : coinList) {
        if (excludedCoinType == coin) {
            sb.append(0 + " x " + coin + "p, ");
        } else {
            sb.append(totalCoinValue / coin + " x " + coin + "p, ");
            totalCoinValue = totalCoinValue % coin;
        }
    }
    sb.append(" with a remainder of " + totalCoinValue + "p");
    return sb.toString();
}