1. CSCI-235 Micro-Computer Applications
Programming: Part I

2. Programming
Program – a set of detailed, step-by-step instructions that directs the computer to do what you want it to do
Programming language – a set of rules that provides a way of telling the computer what operations to perform
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3. The Programming Process
Five main steps
Defining the problem
Planning the solution
Coding the program
Testing the program
Documenting the program
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4. Defining the Problem Develop a written agreement that specifies:
The input data
The desired output
Sometimes, the programmer receives a written specification from the systems analyst
Other times, the programmer meets with users directly
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5. Planning the Solution
Algorithm – a detailed, step-by-step solution to the problem
Several tools help plan the algorithm
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6. Planning Tools Flowchart – a pictorial representation of the algorithm
Pseudocode – English-like language
Specifies algorithm with more precision than you can in English, but less than a programming language
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7. Coding the Program
Translating the algorithm from the planning stage into a formal programming language
All languages have syntax rules
Similar to grammatical rules
The computer will reject a program with even a minor syntax error
Programs can be keyed into the computer by using a text editor
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8. Programming Languages
Assembly Language
Machine Language
Fortran
Pascal
COBOL
BASIC
Ada
Visual Basic
C and C++
Java
Smalltalk
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9. Testing the Program Two phases of testing the program Translation
Converting the program you wrote into the binary instructions the CPU understands
Debugging
Identifying and correcting logic errors in the program
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10. Translation
Compiler translates the program (source module) into a machine language version (object module)
If the compiler detects syntax errors, it will produce messages describing those errors
If no syntax errors exist, the object module will be linked to create a load module
Load module is executed by the computer
EXAMPLE
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11. Documenting the Program
Materials are generated at each part of the process
Common examples of documentation
Flowchart and/or pseudocode
Comments within the source code
Testing procedures
Layouts of input and output records
A narrative description of the program
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12. Levels of Languages
Lower-level languages – more like the 0s and 1s the computer itself uses
Higher-level languages – more like the languages people use
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13. Machine Language
Programs and memory locations are written in strings of 0s and 1s
Problems with machine languages
Programs are difficult to write and debug
Each computer has its own machine language
Only option available to early programmers
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14. Machine Language Machine language:
Consists of binary numbers (0s and 1s)
Is the earliest programming language
Is the only language the computer understands without translation
Is machine dependent
Each family of processors has its own machine language
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15. Assembly Languages Substitute mnemonic codes for 0s and 1s
For example, A for add, C for compare, etc.
Use names rather than binary addresses for memory locations
Require an assembler to translate the program into machine language
Still used for programming chips and writing utility programs
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16. Assembly Languages Assembly language: Resembles machine language
Is a low-level language
Uses brief abbreviations for program instructions
Abbreviations are called mnemonics
A program is written in source code (text file) and translated into machine language by an assembler
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17. High-Level Languages Transformed programming
Programmers could focus on solving problems rather than manipulating hardware
Programs could be written and debugged much more quickly
Requires a compiler to convert the statements into machine language
Each computer has its own version of a compiler for each language
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18. High-level Languages High-Level languages:
Create programs at a high level of abstraction
Are easier to read, write, and maintain than machine and assembly languages
Use a compiler or interpreter to translate code
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19. Compilers and Interpreters
A compiler is a program that changes source code to object code
An interpreter translates source code one line at a time and executes the instruction
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20. Major Programming Languages
FORTRAN
COBOL
BASIC
Visual Basic C
Java
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21. FORTRAN The first high-level language Stands for FORmula TRANslator
Used primarily for engineering, mathematical, and scientific tasks
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22. COBOL Stands for COmmon Business-Oriented Language
Used primarily for business requirements
Processes large data files
Produces well-formatted reports
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23. BASIC Stands for Beginners’ All-Purpose Symbolic Instruction Code
Developed to teach programming to college students
Became very popular with the introduction of the microcomputer
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24. C Originally designed to write systems software
Offers the ease of use of a high-level language with the efficiency of an assembly language
Very portable – can be used with virtually every combination of computer and operating system
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25. Java
A network-friendly programming language that permits a piece of software to run directly on many different platforms
Allows programmers to write one version of the program, rather than a separate version of each platform
Very useful for Internet development
Java applets can run in the user’s Web browser
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