Sample Main.java for a BankAccount problem

public class Main {

	public static void main(String[] args) {
		// Here is what happens when this line of code is executed:
		BankAccount acct = new BankAccount(1000.55);
		// new finds a place in memory to put a virtual BankAccount,
		//   places it there, and returns the memory location
		// = is called an assignment operator; much like + adds numbers
		//   and * multiplies them, = is also an operator.  The expression
		//   to the right of = is computed, and then the variable on the
		//   left of the = is assigned that value.  Since new returns a
		//   memory location, acct is actually assigned a location in memory.
		//   We can see this by printing acct:
		System.out.println(acct);
		// The output is BankAccount@HEXADECIMAL_MEMORY_LOCATION
		//
		// Going back to the first line of code, the BankAccount
		// on the far left does not actually have anything to do with
		// what is placed in memory.  Rather, when acct is used, it
		// determines how acct is supposed to be viewed by Java.  It
		// probably seems trivial to say that acct should be a BankAccount,
		// but later in the class, we will see situations where other
		// approaches make sense.  (The topic is "polymorphism" for
		// hotshots who want to look ahead.)
	}

}