Thread: If Else Flow Charts

What part of this is giving you trouble? Can you draw a flowchart? Can you write the if statement?

Originally Posted by bakemono44

I can write a program.. but I dont understand how to write the questions into flow charts or flow charts to the program..

The thing about flow charts is that they are actually harder to keep straight (no crossed lines) if the program logic is sloppy. That's one reason they used to be required for lots of things, like Military/Aerospace projects. Nowadays, structured pseudo-code seems to be the norm.

I didn't even know they were still teaching flow charts. Or, considering your professed cluelessness, maybe they aren't actually teaching them, just giving assignments.

Anyhow...

A language-agnostic (no particular computer language, that is) flow chart derived directly from the specification might look like the following.

Forgive the butt-ugly ASCII "graphics" for diamond-shaped decision boxes and oval-shaped enter/exit boxes. The parallelogram I/O boxes came out pretty good, I'm thinking.

I mean, I could have done it in Visio (or Inkscape) and attached a "real" graphics file, but this way was more fun. (I have been told that I have a very peculiar idea of "fun," but keep in mind that this is not my home planet, and I take my "fun" anywhere I can find it.)

Anyhow...

      _______
     (       )
    (  Enter  )
     (_______)
          |
          |
          |
          V
          /\
        /    \ 
      /        \
    /     A has  \   Yes
   <     +sign    >--------->----------------+
    \      ?     /                           |
      \        /                             |                    
        \    /                               V
          \/                                 |
           | No                              |
           |                                 |
           V                                 V
           /\                                /\
         /    \                            /    \ 
       /        \                        /        \
     /    B has   \ Yes                /    B has   \   Yes
    <     -sign    >------>----+      <     +sign    >------->-------+
     \      ?     /            |       \      ?     /                |
       \        /              |         \        /                  |
         \    /                V           \    /                    V
           \/                  |             \/                      |
           | No                |             | No                    |
           |                   |             |                       |
           |           ________V______       |               ________V______
           |           \              \      |               \              \
           |            \     Print    \     |                \     Print    \
           V             \   "NEGATIVE" \    V                 \   "POSITIVE" \
           |              \______________\   |                  \______________\
           |                   |             |                       |
           |                   V             |                       V
           |                   |             |                       |
           |<----------<-------+             |<----------<-----------+
           |                                 |
           V                                 V
           |                                 |
           |<----------<------------<--------+
           |
           V
           |
           |
        ___V___
       (       )
      (  Exit   )
       (_______)

Now, this is not tied to any particular computer language, but it does imply that the programmer has to know what it means for a number to have a "plus sign" or a "minus sign." It also assumes, that for purposes of this program, that every number has either a "plus sign" or a "minus sign." That distinction may or may not be important, depending on whether the person who made the assignment accepts zero as as a number with a "plus sign" or not. (Otherwise, the program would have to be modified a little to accommodate zero as having neither a "plus sign" nor a "minus sign.")

Zero isn't, really a positive number, of course, but people seem to want all integers in the computer to be either positive or negative, and most would simply not accept zero in the 2's complement number system (which is what Java uses) as a negative number, so...

A reference: Flowchart - Wikipedia

Bottom line: There are about a million ways to write the program, but if you do the flow chart first and make it neat (no crossed lines), the program implementation in just about any procedural language is (almost) trivial.


Cheers!

Z