Collection (gb)

This class implements an hash table whose keys are String and values are Variant.

NULL is used when nothing is associated with a given key. Consequently, associating NULL with a key is the same thing as removing it from the collection.

The size of the internal hash table grows dynamically as data is inserted.

This class is creatable.

This class acts like a read / write array.

This class is enumerable with the FOR EACH keyword.

Properties
Count   Returns the number of elements stored in the collection.
Default   Return or set the collection default value that is returned when no value is associated with a key.
Empty   Return if the collection is empty.
First   Returns the key of the first element inserted in the collection, or NULL if the collection is void.
Key   Returns the key of the last read or last enumerated element.
Keys   Return a string array of all collection keys.
Last   Returns the key of the last element inserted in the collection, or NULL if the collection is void.
Length   Returns the number of elements stored in the collection.

Methods
Add   Adds an element to the collection.
Clear   Clears the collection.
Copy   Returns a copy of the collection.
Exist   Returns if something is associated with this key in the collection.
Remove   Removes an element from the collection.

Example

PUBLIC SUB Main()

  DIM cAbbr2Weekday AS Collection = ["mo": "Monday", "tu": "Tuesday", "we": "Wednesday", "th": "Thursday", "fr": "Friday", "sa": "Saturday", "su": "Sunday"]
  DIM cCopy AS Collection
  DIM sAbbr AS String
  
  ' To access the data
  PRINT cAbbr2Weekday["fr"]
  
  ' Print mapping key to value
  FOR EACH sAbbr IN cAbbr2Weekday
    PRINT cAbbr2Weekday.Key & " --> " & sAbbr
  NEXT

  ' Lenght/Count return both 7
  PRINT cAbbr2Weekday.Count
  PRINT cAbbr2Weekday.Length

  ' Add element and remove it again
  cAbbr2Weekday.Add("sat", "Saturday")
  cAbbr2Weekday.Remove("sat")
  
  ' Test if a key is present
  PRINT cAbbr2Weekday.Exist("we")
  
  ' Make a copy and clear the original collection
  cCopy = cAbbr2Weekday.Copy()
  cAbbr2Weekday.Clear()

END