Types of computer language

Machine language

§  Understood directly by the microprocessor but difficult for humans

Higher-level language   

§  Visual Basic is an example of this it consist of intructions that people can relate

What is GUI?

Graphical user interface

o   They programs employ objects such as windows, icons and menus that can be manipulated by a mouse,

o   Non-GUI-based programs use only text and are accessed solely via a keyboard

How do we get computers to perform complicated tasks?

Tasks are broken in to sequences

 Also referred to as a developer is a person who solves problems by writing programs on a computer.

This is any person who runs a program

Most programs do 3 things

 Take in data (input),

Manipulate data (processing),

 Produce desired results (output)

o   Input data might be held in a  program, on a disk, or provided by a user

o   Processing is done internally and can vary in time

o   Output is displayed on the monitor, printed or recorded on a disk

  Zero-based numbering system

  Counting begins with zero instead of one

The physical components of the computer, including all peripherals, the central processing unit, disk drives, and all mechanical and electrical devices.

These are the programs

How are problems solved with a program?

§ 

Problems are read to determine what data are given and what outputs are requested. Then a step-by-step procedure is devised to process the given data and produce the requested output.

Performing a Task on the Computer

3 steps

§  First determine what the desired output will be.

§  Second, Identify the data, or input, necessary to obtain the output.

§  Third, determine how to process the input to obtain the desired output ( what formulas or ways of doing things should be used to get the desired output)

Programing Planning

§  Software Development Life Cycle - A sequence of steps

o   Analyze – Define the Problem

§  Have an understanding of what the program needs to do (output)

§  Have a clear idea of what data (input) are given and the relationship between the input and the desired output

o   Design – Plan the solution to the problem

§  Find a logical sequence of precise steps that solve the problem

·         These type of steps are called an Algorithm

o   Ever step including the obvious steps, should appear in the algorithm.

o   Design the interface – Select the objects (text boxes, buttons, etc.)

§  Determine how the input will be obtained and how the output will be displayed. Then create objects to receive the input and display the output. Also, create appropriate buttons and menus to allow the user to control the program.

o   Code – Translate the algorithm into a programming language

§  Coding is the technical word for writing the program. During this stage, the program is written in Visual Basic and entered into the computer. The programmer uses the algorithm devised in Step 2 along with knowledge of Visual Basic.

o   Test and Correct – Locate and remove any errors in the program

§  Testing is the process of finding errors in a program ( this is also called a  Bug and testing and correcting is often referred to as Debugging)

o   Complete the Documentation- Organize all the material that describes the program

§  Documentation is intended to allow another person or the programmer at a later date, to understand the program. This could be a detailed description of what the program does and how to use it. Although documentation is listed as the last step it should take place as the program is being coded.

PROGRAMMING TOOLS

§  Three tools used to convert algorithms into computer programs

o   Flowcharts

o   Pseudo code

o   Hierarchy charts

Graphically depict the logical steps to carry out a task and show how the steps relate to each other

   Used to connect symbols and indicate the flow of logic

Used for input and output operations, such as reading and displaying. The data to be read or displayed are described inside

Used for arithmetic and data-manipulation operations. The instructions are listed inside the symbol

Used for any logic or comparison operations. Unlike the input/output and processing symbols, which have one entry and one exit flowline the decision symbol as one entry and one exit paths. The path chosen depends on whether the answer to a question is “yes” or “no”

Used to provide additional information about another flowchart symbol