Procedure problem

[nonamedude]

What is it you are trying to achieve?
A store program


What is the problem you are having?
The program works fine but if the user reapeats it it stops because of the procedures, (i cant use one thats not global to the rest)

Describe what you have tried to solve this problem
Do the whole program as one procedure but it just meeses it up

NOTE: I can only use limited code to this this program(its not like i dont want to it just that i want to do it using what i studied)
loops
for loops
procedures
arrays
if statements (boolean values)
counters
and thats about it (and the basics of course)


Post any relevant code (You may choose to attach the file instead of posting the code if it is too long)
<Answer Here>

Turing:

var game1 : string var game2 : string var game3 : string var view : array 1 .. 1000 of int var answer : array 1 .. 1000 of string var quantity : array 1 .. 1000 of int var response : string var back : string var name : array 1 .. 1000 of string name (1) := "Game 1" name (2) := "Game 2" name (3) := "Game 3" var product : array 1 .. 1000 of real product (1) := 29.99 product (2) := 30.99 product (3) := 19.99 var times : int procedure productsondisplay     cls     loop         times := 0         put ""         put "We have items on display today, please have a look at it"         put "Game1"         put "Game2"         put "Game3"         put "To view a game you are interested in buying please enter the game's No"         times := times + 1         get view (times)         exit when view (times) = 1 or view (times) > 1         cls     end loop end productsondisplay procedure buy     put "How many would you like buy?" ..     get quantity (1) end buy procedure buy1     loop         put "Would you like to go back to the products"         get back         if back = "yes" or back = "Yes" then             productsondisplay         else             if back = "no" or back = "No" then                 put "Please enter bill to show your purchases"                 get response                 if response = "bill" or response = "Bill" then                     put "This is your bill"                 end if             end if         end if         exit when back = "yes" or back = "Yes" or back = "no" or back = "No"     end loop end buy1 procedure gamea     put "picture"     put ""     put ""     put ""     put ""     put ""     put "Requirements"     put "price"     put "How many would you like buy?" ..     get quantity (1)     buy1     cls end gamea procedure gameb     put "picture"     put ""     put ""     put ""     put ""     put ""     put "Requirements"     put "price"     put "How many would you like buy?" ..     get quantity (2)     buy1     cls end gameb procedure gamec     put "picture"     put ""     put ""     put ""     put ""     put ""     put "Requirements"     put "price"     put "How many would you like buy?" ..     get quantity (3)     buy1     cls end gamec procedure games     if view (1) = 1 then         put "picture"         put ""         put ""         put ""         put ""         put ""         put "Requirements"         put "price"         put "How many would you like buy?" ..         get quantity (1)         buy1         cls     else         if view (1) = 2 then             put "picture"             put ""             put ""             put ""             put ""             put ""             put "Requirements"             put "price"             put "How many would you like buy?" ..             get quantity (2)             buy1             cls         else             if view (1) = 3 then                 put "picture"                 put ""                 put ""                 put ""                 put ""                 put ""                 put "Requirements"                 put "price"                 put "How many would you like buy?" ..                 get quantity (3)                 buy1                 cls             end if         end if     end if end games procedure bill     if view (times) = 1 then         put             name (1), product (1), quantity (1)     else         if view (times) = 2 then             put                 name (2), product (2), quantity (2)         else             if view (times) = 3 then                 put                     name (3), product (3), quantity (3)             end if         end if     end if end bill productsondisplay games bill

Please specify what version of Turing you are using
4.1.1.0

[Dusk Eagle]

First of all, your arrays should not be going from 1 to 1000. This is a terrible programming practice for many reasons. You should either make them contain only as many elements as you need, or you should use flexible arrays if you are not sure how many elements you will need.

Secondly, you are using procedures wrong (but good job for using them in the first place!). Procedures should not be modifying the value of variables that are declared outside their scope (i.e. outside of themselves). You should probably look into functions and parameters here. Note that any variables a procedure relies upon that are not passed in as parameters should be declared inside the procedure itself, and not outside.

As for the problem with your code, it lies right here:

Turing:

put "Would you like to go back to the products"     get back     if back = "yes" or back = "Yes" then         productsondisplay

When this condition occurs, it will properly go back to productsondisplay, but then have no where to go. What you should do instead is:

Turing:

loop     productsondisplay     games     bill     put "Buy again?"     get answer %or whatever variable you use     exit when answer ~= "yes" end loop

One more thing: What do you think the following piece of code is supposed to do, anyway? Why are you setting time to zero every time only to increment it by one? Why does "view" have 1000 elements when you only use the first? Why do you have a loop that will always exit the first time through, assuming the user entered a positive number?

Turing:

times := times + 1     get view (times)     exit when view (times) = 1 or view (times) > 1

[Dusk Eagle]

First of all, your arrays should not be going from 1 to 1000. This is a terrible programming practice for many reasons. You should either make them contain only as many elements as you need, or you should use flexible arrays if you are not sure how many elements you will need.

Secondly, you are using procedures wrong (but good job for using them in the first place!). Procedures should not be modifying the value of variables that are declared outside their scope (i.e. outside of themselves). You should probably look into functions and parameters here. Note that any variables a procedure relies upon that are not passed in as parameters should be declared inside the procedure itself, and not outside.

As for the problem with your code, it lies right here:

Turing:

put "Would you like to go back to the products"     get back     if back = "yes" or back = "Yes" then         productsondisplay

When this condition occurs, it will properly go back to productsondisplay, but then have no where to go. What you should do instead is:

Turing:

loop     productsondisplay     games     bill     put "Buy again?"     get answer %or whatever variable you use     exit when answer ~= "yes" end loop

One more thing: What do you think the following piece of code is supposed to do, anyway? Why are you setting time to zero every time only to increment it by one? Why does "view" have 1000 elements when you only use the first? Why do you have a loop that will always exit the first time through, assuming the user entered a positive number?

Turing:

times := times + 1     get view (times)     exit when view (times) = 1 or view (times) > 1

[nonamedude]

ok lots of questions....
gimme a sec to look things through

[nonamedude]

ok i dont want to set my time to 0 i want it to take time every time and add one to it.< every time it loops

I tried what you said but oen problem it only displays the product that i bought, i need it to display everything...
and i stote 1..1000 because i am uncertain of the amount<------ please tell me any disavantages of this vs storing it to the number of elements you need

I took a look at the walkthorugh and i'd love to use those codes but i as i said before it is not that i dont want to its just i need to do it with what i learnt so far

[nonamedude]

If there are guys who answer i might nt be able to answer for a few hours because i wont be online

[nonamedude]

Anyone there?

[jbking]

nonamedude @ Thu May 28, 2009 6:20 pm wrote:

I tried what you said but oen problem it only displays the product that i bought, i need it to display everything...

How is the procedure supposed to know all the other stuff it is supposed to show? This is where a parameter can be useful I think.

[nonamedude]

ok i'll try and read the parameters walkthrough but if there is a way of doing this wihtout using parameters please tell me cause i was supposed to be able to do this wthout any additional code (to the one i mentioned above)

[nonamedude]

Is there a way to make this work cause i am seriously stuck, i got a hint that if i use for loops and store the info in arrays it would make this much easier but i cant seem to get it right . An example would be great

[tjmoore1993]

Turing:

procedure BLAH (number :int) end BLAH %calling it BLAH (2390349)

Use a procedure like that can help a lot because you have too many of them for such a simple program. Looping it would also work.

[nonamedude]

ok..... so hw would that help me with the bill<----- thats my main problem
i need to display everthing the customer bought but in the end i only display what he recently bought

[tjmoore1993]

Turing:

var Selection, Name : string var SelectionOK, stream : int var ItemExists : boolean := false var Price : real procedure Product (Item : int)     loop         if File.Exists ("Data/Item." + intstr (Item) + ".data") then             open : stream, "Data/Item." + intstr (Item) + ".data", get             get : stream, Name             get : stream, Price             close : stream             ItemExists := true             exit         else             ItemExists := false             put "The item you are trying to buy does not exist."             delay (1000)             exit         end if     end loop end Product loop     loop         cls         put "Welcome to my shop, what would you like to buy?"         % Have selection right here         loop             get Selection             if strintok (Selection) then                 SelectionOK := strint (Selection)                 exit             else             end if         end loop         Product (SelectionOK)         if ItemExists = true then             exit         end if     end loop     put "Name : ", Name     put "Price : $", Price     % action HERE     delay (20000000) % remove later... end loop

Sample of what could be a better approach.

Edit*
Flexible arrays will help you when you are figuring out which items you bought by creating a new array each time you bought something. Why not array? Think of it this way... If someone bought 15 items or more you'd need to define a large array and it still might not be enough. Flexible array allows you to change the array allowing maximum efficiency.

Figure out your program first before you do so, maybe ask questions about it as well.

[nonamedude]

Ok the program works fine but i dont understand any of the codes, it is nt that i want do not want to learn them but i have to be able to do this assignment withought using codes tthat i did nt study
i gt
arrays <--- hw to store them in arrays
procedure<------ basic procedure
counters
loops, for loop
if staments

i would gradly aprreciate it if you gave me an example using these, in the meantime i'll work on the one you gave me

[tjmoore1993]

Turing:

procedure Action (WhichAction : int) if WhichAction = 1 then put 1+2 elsif WhichAction = 2 then put 1000 + 337 end if end Action Action (1) % or procedure Action (WhichAction : string) if WhichAction = "FLY" then put 1+2 elsif WhichAction = "JUMP" then put 1000 + 337 end if end Action Action (JUMP)

I do not know how to explain this as good but guides do help and give great descriptive sentences on this stuff. Also, about the I/O portion of the code stream is basically another word for moving data (in and out). When you want to retrieve data you can use a 'read' or 'get' statement or vice versa 'write' or 'put'.

Boolean is another way of saying 'true' or 'false'.

Also notice how in the procedure when I give it a number it loads that file thus allowing ultimate efficiency because you do not need to load things you will probably not look at but load things when you want to see them.