在java w/o循环中以列表格式打印数组列表。

I am trying to re-define the method toString(), which has to return a String, to print an array list called cards with type Card. Because toString() has to return a string I can't use a loop to print out each element one by one, yet I want to print the array list in a list format. Basically, does anyone know how to make toString() return the array list cards as a string without using a loop?I am trying to re-define the method toString(),