posted Aug 3, 2014, 3:39 AM by Maurice Nyamoti   [ updated May 11, 2015, 9:20 AM ]

Flow Charts

Flow charts are used to represent any well defined sequence of activities. they are used to convey in diagrammatic form, the logic, processing operations and flow of control required of a computer program

Uses Of Flowcharts

Flowcharts are used by programmers to:

  1. To plan the structure of a program before it is written
  2. To describe the structure of a program after it has been written

Flowchart Symbols

Flowchart symbols are combined with short text clues which are a form of shorthand understood by programmers. Below is a list of symbols:
 1- Start/Stop
 Ellipse: denotes the beginning and end of the program algorithm
 2- Input/Output
 Parallelogram: used to denote an input or output operation. For example, READ A, B, PRINT SUM
 3- Process
 Rectangle: Indicates that a processing or data transformation is taking place. For example SUM = A+B
 4- Decision
 Rhombus: Used to specify a condition. A condition must evaluate to a Boolean value (true or false) for the program to execute the next instructions
 5- Connector
 Circle: Used as a connecting point or interface for arrows coming from different directions
 6- Arrow
 Arrow: Used to indicate the direction of flow of the program logic

Guidelines For Drawing a Flowchart

  1. there should be only one entry/starting point and one exit point of the program algorithm - except for decisions and connectors
  2. Use the correct symbol at each stage in the flowchart
  3. The logical flow should be clearly shown using arrows.
  4. Use connectors to reduce the number of flow-lines
  5. Add notes if necessary, but don't clutter the diagram
  6. Lines should ideally be vertical or horizontal