When we were using arrays, we could rewrite entries by using bracket notation to reassign values:

String[] shoppingCart = {"Trench Coat", "Tweed Houndstooth Hat", "Magnifying Glass"};

shoppingCart[0] = "Tweed Cape";

// shoppingCart now holds ["Tweed Cape", "Tweed Houndstooth Hat", "Magnifying Glass"]

ArrayList has a slightly different way of doing this, using the set() method:

ArrayList<String> shoppingCart = new ArrayList<shoppingCart>();

shoppingCart.add("Trench Coat");
shoppingCart.add("Tweed Houndstooth Hat");
shoppingCart.add("Magnifying Glass");

shoppingCart.set(0, "Tweed Cape");

// shoppingCart now holds ["Tweed Cape", "Tweed Houndstooth Hat", "Magnifying Glass"]