comprog

Computer

is an electronic device that accepts data from the user, processes it, produces results, displays them to the users, and stores the results for future usage.

Data

 is a collection of unorganized facts & figures and does not provide any further information regarding patterns, context, etc. Hence data means "unstructured facts and figures".

Information

is a structured data i.e. organized meaningful and processed data. To process the data and convert into information, a computer is used

hardware

refers to mechanical device that makes up computer.

Software

 a set of instructions that drives computer to do stipulated tasks is called a program. Instructions are programmed in a computer language, translated into machine language, and executed by computer.

System software

operates directly on hardware devices of computer

Application software

 is designed for benefit of users to perform one or more tasks.

Example: Microsoft Word, Excel, PowerPoint, Oracle, etc.

Programming

procedure of developing the detailed instructions for the computer.

programming step

1. Define the problem

2. Design the solution/program

3. Code the program

4. Test the program

5. Document the program

problem definition step

1. Specify program objectives and identify the users of the program.

2. Specify output requirements.

3. Specify input requirements.

4. Specify processing requirements.

5. Study feasibility of implementing the program.

6. Document the analysis.

Program coding

is the step which translates the logic of the program based on the pseudo-code (algorithm) or flowcharts into a high-level programming language using the syntax and semantics of the specific language.

Program testing

consists of desk checking, debugging, and running real data to make sure that the program works.

Desk checking

 is just reading through or checking the program manually to ensure that it is free from errors and the logic works.

Debugging

means detecting, locating, and removing errors in the computer program.

Error

may be syntax errors or logic errors.

Syntax errors

can be typographical error or incorrect format of the statement used. 

Logic errors

 are caused by incorrect use of control structures.

Program logic formulation

is a step-by-step development of a solution to a given problem. This is the most difficult part of solving a problem with a computer

Flowchart

It consists of boxes with different shapes that contain simple statements or sentence commonly called instructions and connect together by lines.

Stored Data Symbol

Indicates data stored in formats suitable for processing

Sequential Access Storage

Indicates only sequentially accessible data such as those on magnetic tapes & cassette tapes

Direct Access Storage

Indicates directly accessible data, such as those on magnetic disks & floppy disks

Documents

Indicates data on media human beings can read

Display

Indicates data on any medium that displays information used by human beings, such as monitor

Loop Limit

Composed of two parts; condition for termination and loop name are written in the symbol indicating the start & the end of the loop respectively

Terminal Symbol

contains either the word start or the word stop, indicates the starting and stopping point in the flowchart.

This parallelogram is used for INPUT and OUTPUT instruction.

Processing Symbol

This rectangle is used for ay data processing operations for which requirements of the problem are usually done here.

Decision Symbol

If the condition is true, the marked path TRUE is to be followed. If the condition is false, the marked path FALSE is to be followed. This diamond-shaped symbol contains a condition.

Arrowheads/Flow lines

used to direct the flow of the flowchart. It shows the flow of the solution.

Connector

It is used as a continuation symbol of a flowchart. It shows the flow of the solution.

Initialization/Preparation Symbol

It is used to initialize variables not explicitly defined in the input but a requirement in the production of the output.

System Flowchart (process chart)

indicates a flowchart for a targeted system as a whole

Program Flowchart

is used to describe processing procedures based on detailed analysis.

Structured Flowchart

An orderly, understandable and clear solution. Design using the three most basic methods of control.

Sequential

steps are performed in a strictly sequential manner, each step being executed exactly once.

Selection Structure

One of several alternative actions is selected and executed. It involves the use of decision based on the given condition.

Repetition Structure

One or more steps is performed repeatedly

Algorithm

set or series of instructions for carrying a task. It is also a procedure to produce the required output from the given input.

Pseudo code

 is a mixture of language and symbols, terms and other feature commonly used one or more high-level languages.

Turbo C

more than just a version of the C language.

Compiler

is used to convert source code into machine code or binary code.

Debugger

is used for testing program and locating programming errors.

int variables

is whole number consisting of an optional sign (+ or -) followed by a sequence of digit. It cannot contain commas. Variables of this type are often used for controlling loops and conditional statements.

float

consists of an optional sign (+ or -), followed by one or more digits, a decimal point, and or one or more further digits.

double (double precision)

is a special float which can store more significant digits and have a longer exponent.

char

is a single letter, digit, punctuation mark or control symbol recognized by the computer.

void

valueless

Variables

are identifiers which can be assigned a value within a program. It has 32 valid characters, and these are letters, digits, and underscore.

Global Variables

are initialized only at the start of the program. All global variables are initialized to zero if no other initializer is specified.

Local Variables

are initialized each time the function in which they are declared is entered.

Constants

refer to fixed values that may not be altered by the program.