Flowchart in programming

Learning and using flowchart in programming will have effective and efficient coding. It is not a compulsory. However, the flowchart assist visualize of process or algorithm (better then pseudo code); will help better understanding, analyze and debug in later (or by other).

Flowchart in computer programming is a “language-less” tool that capable to shows the logical flow and program structure. Back in old days (199x), we have to draw out program flowchart manually with the help of template as fig.1. Nowadays, any drawing program can be used to draw flowchart. More wonderful, there are software’s that can create flowcharts automatically, either directly from source code, or from a flowchart description language.

Figure 1: Flowchart template for quick drawing (old collection by now :) )

As seen in template, below are some basic elements of flowchart in programming.

Start and end symbols - represented by rounded rectangles. Usually, it is containing the word "Start" or "End”.

Arrows – represent flow of computer program from one step to another.

Process - represented by rectangles. It is containing the action needed to be performing (in small and meaningful portion).

Auxiliary operation (or sub-process) – represented by square (normally square fit with rectangle). It is use to show sub-process (i.e. sub-function, sub-routine, sub-program etc) that help to process.

Input/Output - represented by parallelogram. It is used to get input from the user or output to display/storage.

Decision (or conditional) - represented by a diamond (rhombus). It is typically contain short question test, and with 2 branch out Yes/No or True/False. The branch out arrows should always be labeled. There are possible more than two outcomes, i.e. three (?? ;-) ) or by cascading conditional (four or more).

Online storage (or Data File) - represented by a cylinder. This is used to show recording of data with always online media.

Offline storage (or Data File) - represented by inverse triangle. This is used to show recording of data with removable media.

Document - represented by rectangle with a wavy base. This is used to show create printout hardcopy document.

Manual input - represented by rectangle with the top irregularly sloping up from left to right. Mostly, it is used to show a form data-entry.

Manual operation - represented by a trapezoid with the longest parallel side at the top. It is show operation or process can only be made manually.

Connectors - represented by circles. It is used to connect paths in the flow chart. Each circle must be labeled by numbering 1, 2, 3 … etc to clearly differentiate the converging paths.

Off-page connectors – represent by a “tag” rectangle with triangle pointing left. It is used to signify a connection to a step held on another sheet or screen.

There is ISO standard for flowchart symbols in computer programming. However, some symbols are start showing “old age”. Not many younger generation programmers will know and appreciate “punched card”, “punched tape”, “magnetic tape”, etc… kind of symbols.

Basic concept of flowchart usage is all processes should be flow from top to bottom and left to right (however, there is some exceptional. :-)  ).