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15 – Structured Programming
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Admin: Coursework 3 – Test
In class test 7 Feb 2011 31 Jan 2011: revision (technique) session 50 mins short answer (5 - 6 words max) 25% of module mark
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Questions: Functions Consider the following code: Function Smallest(num1, num2) If num1 < num2 Then Smallest = num1 Else Smallest = num2 End If End Function name a function. what is left in small after the following is executed? Dim small small = Smallest(23, 15) Smallest 15
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Session Aims & Objectives
To highlight the fundamental ideas of the structured programming paradigm Objectives, by end of this week’s sessions, you should be able to: create an abstract data type, which includes data, and routines use this to reduce code length
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Example: Ball Bounce v1 <html>
<head><title>Ball Bounce</title></head> <body style="margin: 0;"> <img id="imgBall" src="Ball.gif" style="position: absolute;" /> </body> </html> <script language="vbscript"> Option Explicit Dim x Dim y Dim xInc Dim yInc Sub window_onLoad() window.setinterval "Main()", 20 xInc = 5 yInc = 3 End Sub Sub Main() x = imgBall.style.posLeft + xInc If x <= 0 Or x >= document.body.clientWidth - imgBall.width Then xInc = -xInc Else imgBall.style.posLeft = x End If y = imgBall.style.posTop + yInc If y <= 0 Or y >= document.body.clientHeight - imgBall.height Then yInc = -yInc imgBall.style.posTop = y </script>
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Structured Paradigm Program made up of
data structures, and routines (procedures and functions) that process the data within those structures. Each routine should perform a single, clearly identifiable operation. Each routine should be self-contained Abstract data type = structure + procedures
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Example: Ball Bounce v2 Sprite.vbs BallBounce.htm Option Explicit
Dim x Dim y Dim xInc Dim yInc Sub Init(tmpXInc, tmpYInc) xInc = tmpXInc yInc = tmpYInc End Sub Sub Move(img) x = img.style.posLeft + xInc If x <= 0 Or x >= document.body.clientWidth - img.width Then xInc = -xInc Else img.style.posLeft = x End If y = img.style.posTop + yInc If y <= 0 Or y >= document.body.clientHeight - img.height Then yInc = -yInc img.style.posTop = y BallBounce.htm <html> <head><title>Ball Bounce</title></head> <body style="margin: 0;"> <img id="imgBall" src="Ball.gif" style="position: absolute;" /> </body> </html> <script language="vbscript" src="Sprite.vbs"></script> <script language="vbscript"> Option Explicit Sub window_onLoad() window.setinterval "Main()", 20 Init 5, 3 End Sub Sub Main() Move imgBall </script>
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Example: Balloon Shoot
Question: what objects? what variables? what procedures / functions?
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Tutorial Exercise: Ball Bounce
Learning Objective: To create and use your own class. Task 1: Get the Ball Bounce examples (1, 2, and 5) from the lecture working. Task 2: Add a hit method to the sprite class, which detects the collision with another sprite. Task 3: Modify your page to count the number of hits between the two sprites. Task 4: Modify your page to make sprites bounce off each other. Task 5: Add another sprite.
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Tutorial Exercise: Balloon Shoot
Learning Objective: To create and use your own classes. Task 1: Create the Balloon Shoot example (from the lecture) using object oriented concepts (classes, properties, methods, and instances) hint: use some of the code from your Interceptor example (from last week)
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