As you have stated iterator is used when you want to remove stuff whilst you iterate over the array contents. If you don’t use an iterator but simply have a for loop and inside it use the remove method you will get exceptions because the contents of the array changes while you iterate through. e.g: you might think array size is 10 at the start of the for loop but it wont be the case once you remove stuff.. so when u reach the last loops probably there will be IndexOutofBoundsException etc.