Need major help!

[noncon]

I am completely lost and i need help with this coding.
Any help with the getTotalPriceOfTrolleyItems where I have to get the Total price of the items in the trolley, clearAllItemsFromTrolley is to clear the array and removeItemFromTrolley is to remove an object from the array. Any help with these methods will be greatly appreciated.

public class ShoppingTrolley {
public static final int MAXIMUM_NUMBER_OF_ITEMS = 200;

private Item[] itemsInTrolley;
private int itemsSoFar;

public ShoppingTrolley() {
itemsInTrolley = new Item[MAXIMUM_NUMBER_OF_ITEMS];
itemsSoFar = 0;

}

public int getNumberOfItemsInTrolley() {
return itemsSoFar; //You will need to change this
}

public void addItemToTrolleyIfAvailable(Item itemToAdd) {
itemsInTrolley[itemsSoFar] = itemToAdd;
itemsSoFar++;
itemToAdd.decreaseNumberInStockBy1();

}

public void printTrolleyItems() {
for (int i=0; i <itemsInTrolley.length; i++){
System.out.println (itemsInTrolley[i].getFullDescription());
}
}


public double getTotalPriceOfTrolleyItems() {
double totalPrice = 0;
for (int i = 0; i < itemsInTrolley.length; i++){
totalPrice = totalPrice + itemsInTrolley[i].getPrice();
return totalPrice ;
}
return -1;
}

//You will need to change this





public void clearAllItemsFromTrolley() {
for (int i = 0; i < itemsInTrolley.length; i++){
itemsInTrolley [i] = null;
itemsSoFar = itemsSoFar - 1;
itemsInTrolley[i].increaseNumberInStockBy1();
}
}


public void removeItemFromTrolley(int indexToRemove) {
for(int i = 0; i < itemsInTrolley.length - 1; i++) {
itemsInTrolley[indexToRemove -1] = null;

//itemsInTrolley [itemsInTrolley.length - 1];

[Tolls]

public class ShoppingTrolley {
    public static final int MAXIMUM_NUMBER_OF_ITEMS = 200;
    
    private Item[] itemsInTrolley;
    private int itemsSoFar;
    
    public ShoppingTrolley() {
      itemsInTrolley = new Item[MAXIMUM_NUMBER_OF_ITEMS];
      itemsSoFar = 0;

    }
    
    public int getNumberOfItemsInTrolley() {
      return itemsSoFar; //You will need to change this
    }   
    
    public void addItemToTrolleyIfAvailable(Item itemToAdd) {
      itemsInTrolley[itemsSoFar] = itemToAdd;
      itemsSoFar++;
      itemToAdd.decreaseNumberInStockBy1();

    } 
    
    public void printTrolleyItems() {
      for (int i=0; i <itemsInTrolley.length; i++){
          System.out.println (itemsInTrolley[i].getFullDescription());
        }
      }

    
    public double getTotalPriceOfTrolleyItems() {
      double totalPrice = 0;
      for (int i = 0; i < itemsInTrolley.length; i++){
        totalPrice = totalPrice + itemsInTrolley[i].getPrice();
        return totalPrice ;
      }
      return -1;
      }

//You will need to change this


    

    
    public void clearAllItemsFromTrolley() {
      for (int i = 0; i < itemsInTrolley.length; i++){
        itemsInTrolley [i] = null;
        itemsSoFar = itemsSoFar - 1;
        itemsInTrolley[i].increaseNumberInStockBy1();
      }
    }

    
    public void removeItemFromTrolley(int indexToRemove) {
      for(int i = 0; i < itemsInTrolley.length - 1; i++) {
        itemsInTrolley[indexToRemove -1] = null;
        
        //itemsInTrolley [itemsInTrolley.length - 1];

Please use code tags when posting code, otherwise it loses all formatting.

What problems are you having with those methods?
Compilation errors?
Runtime errors?
Logic (ie incorrect output) errors?

[noncon]

Noted.
I mostly have null pointer exceptions and logic errors.

[Tolls]

So it compiles.

People here aren't going to run your code to see where you are having problems.
You need to tell us what, where, stack traces etc.