CSCI130

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Lecture-10 (6.1-6.6)

• CSCI130
• Instructor Dr. Imad Rahal

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Higher-level Programming Languages (PLs)

• (1GL) Machine language programming
• limited set of instructions
• binary numbers opcodes, absolute memory
  addresses and data
• Memory addresses
• (2GL) Assembly language
• English mnemonics for binary opcodes
• Decimal data
• Labels for memory addresses and variables
• limited instruction set
• Use human languages to program
• Large vocabulary (space and time to search)
  opcode lookup
• 500,000 words - 1,000,000 words (including
  scientific words)
• Synonyms weather and whether
• Homonyms ate and eight
• Context
• Slang

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Higher-level Programming Languages

• (3GL) High-level languages are in the middle
• Use English-like phrases and mathematical
  notation
• x x1
• Do it in assembly?
• A limited vocabulary with precise meaning
• Make us think at a higher-level of abstraction
• No attention to technical and hardware details
• Like O.S.
• Much larger instruction set for programmers
• Multiplication

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Computer Programming

• Different types of high-level languages
• The imperative programming paradigm
• A program is a sequence of instructions
• Machine language/assembly language
• Object-oriented paradigm (just as we, humans,
  think)
• Visual Basic or VB uses the OOP
• Objects each having properties and actions
  Imagine a computer screen with several icons
• Each is a icon is an object also desktop is an
  object
• Each icon has its own attributes and actions
• Properties Icon image/shape and color
• Actions
• Single-clicked ? Darken Color (affect itself)
• Double-clicked ?
• Run corresponding program (Program is another
  object)
• Change desktop look (Desktop is another object)

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Object-Oriented Programming

• The program is collection of interacting objects
• In VB, actions are triggered by events
• Done by users (interactive) e.g. CLICK or
  DOUBLE_CLICK
• Objects sharing properties/methods are grouped
  into classes
• Class An Icon
• Object My Documents, My Computer

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Introduction

• Basic is an imperative language developed in
  1960s
• Visual Basic (VB) --- developed by Microsoft
• OO version of Basic
• Underlying ALL MS office programs
• You could do a lot
• Write your own programs
• Tailor office applications
• Visually oriented
• Programs have a GUI for input/output
• First thing to do to build a VB program is to
  design the interface
• Intro to VB

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Hungarian Notation

• A must in this course
• Every object used MUST be renamed including the
  form(s) using the following rules
• Form ?frmFormName
• E.g. frmTemperature
• Also change caption
• Textbox ? txtTextBoxName
• E.g. txtInputBox
• Also change Text (to empty)
• Label ? lblLabelName
• E.g. lblDescribeInput
• Also change caption
• Button ? cmdButtonName
• E.g. cmdComputeButton
• Also change caption
• PictureBox ? picPictureBoxName
• E.g. picOutputBox