How to Design Logic for a Flowchart That Prints Numbers

Flowcharts use directional arrows to illustrate a process flow.

Designing any logic for a flowchart involves sorting out the necessary logical steps in any given process. Flowcharts use industry standard symbols such as small circles, ovals, rectangles and decisions to represent different types of actions within a process. To design a flowchart to illustrate a number printing process, you'll not only need to draw out the steps to print but also the necessary step of validating that the item the user types in is an actual number before the final print instructions.

Things You'll Need

• Pencil
• Paper
• Flowchart software (optional)

Instructions

1. Write out each step involved in the printing process on a piece of paper. This includes prompting the user to enter an item, validating that the item is a number and then printing the number.

2. Lay out another sheet of paper or open a new file in your flowchart software. Draw or insert an oval shape at the top of the page. Write "Start" inside the oval. Draw a downward straight arrow from the bottom-center of the oval.

3. Insert or draw a rectangle at the bottom of the arrow. Write inside the rectangle, "Prompt user to enter number." Draw another downward arrow straight from the bottom of the rectangle.

4. Insert or draw a diamond shape at the bottom of the last arrow that you drew and make sure that the diamond is on its side so that the long points are pointing out to the left and to the right. Inside the diamond, write "Validate number."

5. Draw an arrow straight out to the left of the diamond and an arrow straight out to the right of the diamond. Above the arrow to the left, write the word "Yes." Above the arrow to the right, write the word "No."

6. Insert a rectangle to the end of the arrow to the left. Write inside the rectangle, "Print number." Insert a rectangle to the right of the arrow on the right and write "Print error message: The character you entered is not a number. You must type a number."

Tips & Warnings

• If you want to get more detailed with your flowchart, include an option below the bottom "Print" rectangle to print to a file rather than to a printer. This will include a decision diamond that could say something like "Print to file?" with the "No" arrow extending from it to a rectangle that says "Print to Printer" instead.

• When creating a flowchart, stick to industry recognized shapes for each intended purpose. For example, always use diamonds for decisions and ovals for start and stop points. Triangles are not used in flowcharts.

References

• "Programming Logic and Design, Fifth Edition"; Joyce Farrell; 2008
• Yale University: CS 112 Introduction to Programming