Methods:

	Why use methods

 	2 types of methods: class, instance

	Steps in using methods

	Example 1 on defining and using method: min

	**** Example 2 on defining and using method: GCD
		not good, need local variable !!!

	Defining a class method - syntax

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	Concept: parameter variable or formal parameter

		1. defined/created when a method is invoked
		2. value of parameter variable is initialized
		   using the values of the actual parameter

	Invoking a class method - behind the scene

		1. value of the actual parameter is copied into
		   formal parameter variables
		2. flow of control is transfered to called method
		3. flow of control is transfered back only upon return
		4. Upon return, the method call is replaced by
		   the value returned


	Method returns:

		1. by executing a "return" statement
		2. when it reach the end of the method definition
		   (in this case, it returns no value)

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	Concept: modular programming 


		A method is a "self-contained" unit
		that performed a well-defined task

		A method usually implements an algorithm

		After a method is written, any user can
		use it WITHOUT knowing the exact steps
		of the algorithm 

		 ---- Method hides the details

		 ---- help to make thinking and problem solving more 
			holostic

	Making self-contained execution units:

		local variables -
			1. created each time a method is invoked
			2. destroyed when a method returns.

		scope of variables

		   method()
		   {

			{
			   int i;
			}

			{
			   int i;
			}
		   }


	Example: 

	Example 1 on modular programming: GCD

	Example 2 on modular programming: LCM

	Example 3 on modular programming: IsPrime

			for i = 2, i <= n/2 ; i++
			   if ( n % i == 0 )
				return (false)
		   	return(true);

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	Parameter passing mechanism:

		1. pass by value

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	Implementing method invocation: call stack

		1. Find all prime number between 2 to n

		   Method calls IsPrime(k)

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	Overloading method name


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	Building Library of methods:

		Math

	Random() method

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  Delay this for later:

	Step-wise refinement
	Top-down design
	divide and conquer

	Case study: text formatting