Can you cast a String to a char by typing: String z = "A"; char zz = (char)z; please help. I get the "inconvertible types" error

That sort of thing won't work in most any language. A string is an array numbers (just known as chars in this case), and a char holds just one number, so they're not compatible. It's no different than trying to cast an array of integers (or any group of integers), to a single integer. Which integer should be used? In your example, you and I both can see that z only contains a single character, but there's no simple way for the compiler to know z will always contain just one. It only knows that z is an array type, that can hold anywhere from zero to millions of characters. You can, however, grab a specific char from the string. For example: char zz = z.charAt(0);