//we had quiz1 and discussions

//look at the completed  BankAccount code from Jan24

/* 
 ----->  static variables (also called Class variables):
	example: see totalNumAccounts variable in BankAccount
	shared by all objects
	if public, can be accessed either by classname.variblename or objectname.variablename
	if private, we usually have getter/setter methods like other variables
	if one object changes the value of a static variable, all other objects
	   see the updated value (remember there is only one variable share by all)

  ----->  static method (also called Class methods):
	methods that only accesses the static data in class
	usually called by classname.methodname(...) but can also use objectname.methodname(...)
	they don't have access to non-static data, why? 
	Example: see getTotalNumAccounts() in BankAccount
	exercise: try to change or access a non-static variable balance or lastName in this method, why doesn't the program compile?
	
   
 -------> Constants:
	cannot be changed after initialized
	used to avoid "magic numbers"! instead of using number 5, e.g., you define a constant called WORK_DAYS and use it instead of number 5. (easier to read the code, and modify it afterwards).
	syntax in java: we use final keyword
	style issue: we use all capital letters, and separate words with _
	example: public static DEPOSIT_FEE = 3.5; 
	note in assignment 1, you need to define a couple of constant in	 the Airport class, and use them in your code.
	
	
	
  -----> Testing code using JUnit
	See BankAccountTester from Jan 24, also RunwayTester from A1
	Here is the general instructions to create a test class for a class called MyClass:
	1. we we extend the TestCase class and call it MyClassClassTester
	    e.g. 
		import junit.framework.TestCase;
		public class MyClassTester extends TestCase {
		   ....
		}

	2. for every public method of our class (including constructors) we write a 'tester method'
	* a tester method for method say "m1" has the following syntax:
		public void testM1(){
			//body
		}
	   where in the body you usually create some objects and call
	   the m1 method. And then check whether the expected values are
	   returned
	   We do this by using "assertTrue"/"assertFalse" or in  general "assertEquals(...)"  

        see examples from A1 and BankAccountTester
        Important: don't forget to put comments for every test case!
	exercise: complete the testWithdraw method in BankAccountTester

	

*/