Associative Array / Pseudo Variables

[Charles Pegge]

Demonstrating the principle though not optimized.

Code Select Expand

'================
'AssociativeArray
'================
indexbase 1 'default
dim string n[1000]
dim string d[1000]
int i,e
'
function dat(string s1,s2)
  for i=1 to e
    if n[i]=s1
      d[i]=s2
      return
    endif
  next
  'new element
  e++
  n[e]=s1
  d[e]=s2
end function
'
function dat(string s1) as string
  for i=1 to e
    if n[i]=s1
      return d[i]
    endif
  next
end function
'
'TEST
'====
'Using Dat(n) as a pseudo variable

dat("A")="1"
dat("B")="2"
print dat("A")
dat("A")=10
print dat("A")
print e


[Zlatko Vid]

This could be useful...
but Charles you made two function with same name dat()
one have 2 arguments and other one ..so what is a purpose?


ps..
...and results are

1 , 10 , 2

...is that correct?
if i understand it e is 2

[Charles Pegge]

I think it is known in the software business as 'function overloading'. The functions have the same name but their parameters are different. When you call a function the compiler picks the function that best matches the parameters. In this case the first function with 2 params is for writing, and the second function with 1 param is for reading.

To make the pseudo variable work, there is another trick:

dat(s1)=s2

is equivalent to:

dat(s1,s2)

You can also do this with the mid function

mid(s1,i)=s2

is the same as:

mid(s1,i,s2)


(yes e should be 2 indicating correct storage of data)

[Zlatko Vid]

I think it is known in the software business as 'function overloading

Aha ..i see ..thanks on explanation Charles..
well i really never do this thing

[Frank Brübach]

My example for o2 and associative array

Code Select Expand

' only the telephone number of alice is not found :-)

uses console

string cr = chr(13,10)

' Creating arrays to store names and telephone numbers
Dim names(4) As String
Dim telephone_numbers(4) As String

' Initializing the arrays with names and telephone numbers
names(1) = "Alice"
telephone_numbers(1) = "123-456-7890"
names(2) = "Bob"
telephone_numbers(2) = "987-654-3210"
names(3) = "Charlie"
telephone_numbers(3) = "555-123-4567"
names(4) = "David"
telephone_numbers(4) = "111-222-3333"

' Function to find the telephone number by name
Function FindTelephoneNumber(namey As String) As String
    Dim names(4) As String
    Dim telephone_numbers(4) As String
    int i
    For i = 1 To 4
        If names(i) = namey Then
            Return telephone_numbers(i)
        End If
    Next
    Return "Not found"
End Function

' Accessing a telephone number by name
Dim namey As String = "Alice"
Dim telephone_number As String
telephone_number = FindTelephoneNumber(namey)
Print "The telephone number of " + namey + " is " + telephone_number + "." cr

' Adding a new entry to the phone book
names(5) = "Eve"
telephone_numbers(5) = "444-333-2222"

' Updating an existing entry
telephone_numbers(2) = "999-888-7777"

' Removing an entry (by setting it to empty)
names(3) = ""
telephone_numbers(3) = ""

' Printing the entire phone book
Print "Phone Book:"
int i
For i = 1 To 5
    If names(i) <> "" Then
        Print names(i) + ": " + telephone_numbers(i) cr
    End If
Next

' Waiting for the user to press a key before closing
wait


[Frank Brübach]

I have made an o2 -> modified example for better understanding with Telephon Numbers and names..
in general would be great to make some more example with oxygen with explanations and comments, thx, frank

Code Select Expand

'
'================
'AssociativeArray
'================
indexbase 1 'default
dim string n[1000] ' Array to store names
dim string d[1000] ' Array to store telephone numbers
int i, e

' Function to add or update a telephone number for a given name
function dat(string name, phone)
  for i = 1 to e
    if n[i] = name then
      d[i] = phone
      return
    endif
  next
  ' If the name is not found, add here a new entry
  e = e + 1
  n[e] = name
  d[e] = phone
end function

' Function to retrieve the telephone number for a given name
function dat(string name) as string
  for i = 1 to e
    if n[i] = name then
      return d[i]
    endif
  next
  return "Number not found" ' Return here a message if the name is not found
end function

'
' TEST
'====
' Using Dat(n) as a pseudo variable to add and retrieve telephone numbers

' Adding telephone numbers
dat("Alice", "123-456-7890")
dat("Bob", "987-654-3210")
dat("Charles", "555-123-4567")

' Retrieving and printing telephone numbers
print dat("Alice") ' Output: 123-456-7890
print dat("Bob")   ' Output: 987-654-3210

' Updating a telephone number
dat("Alice", "111-222-3333")
print dat("Alice") ' Output: 111-222-3333

' Trying to retrieve a number for a name that doesn't exist
print dat("Eve") ' Output: Number not found

' Print the total number of entries
print e ' Output: 3