Question

public class example
{
    public ArrayList<Integer> ToFill = new ArrayList<>();

    public void Alter(int Value , int Position)
    { 
      ToFill.get(Position) = Value ;  // this line has an error 
    }
}

For some reason this code gives compilation Error ,could anyone explain why?

Answer 1

ToFill.get(Position) returns a value where the left-hand side of the assignment must be a variable. Instead, use set(index, element) as follows:

ToFill.set(Position, Value);

However, what you are doing is only valid if you are using arrays, for example:

Integer[] array = ...
array[Position] = Value;

---

As a side note, always use Java naming convention:

• toFill instead of ToFill
• alter instead of Alter
• position instead of Position.
• value instead of Value.