Flow Charting

Goals Create Algorithms using Flow Charting procedures. Distinguish between Flow Charting and Pseudocode. Top-Down Design Bottom-up Design. Symbols used for Flow Charting. Practice problems involving flow charting.

Flow Charting Symbols Oval – Terminals Oval – Terminals Oval symbol represents Start & Stop. Begins all Flow Chart and Ends all Flow Charts.

Subprocess Used 2 different ways. –Represent your declaration where all variables are declared. –Represents a method or procedure in a Top Down design in which each subprocess will have it’s own flowchart.

Input/Output Input/Output – Represents where user either inputs a value usually from keyboard or outputs to the monitor.

Process or Sequence Process box represents where a calculation or action is happening. Use one action per Box

Decision The decision symbol usually represents a loop or an if statement. You have 2 directions to choose from depending if the expression or variable is true or false.

Connectors Connectors are use to join flow charts where you may go to another sheet. Usually has a number in it to match it with the other connector.

Arrows Arrows are used to show the flow of the program.

Do – While Loop

While Loop

If Statement

If – Else Statement

Flow Chart Example

Rules for Flow Charting Every flow chart has a START symbol and a STOP symbol The flow of sequence is generally from the top of the page to the bottom of the page. This can vary with loops which need to flow back to an entry point. Use arrow-heads on connectors where flow direction may not be obvious. There is only one flow chart per page A page should have a page number and a title A flow chart on one page should not break and jump to another page A flow chart should have no more than around 15 symbols (not including START and STOP)

Top Down Design

Wrapping it up A well designed flow chart will make programming easier. Learning the code is not hard. What is hard is applying the code to solve a problem. The more you plan the less time you spend fixing errors.