GAMBAS BOOK 3.19.1

The Gambas interpreter offers you two types of native container classes.

A collection is a collection of items that are indexed using a key of the type string? chapter 7.5 Collection. Only elements of the data type' Variant' can be stored in a collection. The values are stored internally in a hash table that grows dynamically when more elements are inserted into it.

An array is a set of elements that are indexed using an integer type key and stored in a memory block. All elements in an array have the same data type and there is an array class for each native data type.

Arrays can be one- and multi-dimensional. If they are multidimensional, the elements are indexed by more than one integer value. If an array has exactly one dimension, it can be dynamically reduced or expanded using the Resize () method.

Chapters 7.4.0 to 7.4.9 are not only dedicated to the general class array with its properties and methods, but also give an overview of the following topics, with no order of precedence implying the order of precedence:

• Native arrays
• Derived arrays
• One-dimensional arraysMultidimensional arrays (? dimensions)
• Dynamic arrayInline arrays
• Embeded arraysDeclaration of arrays
• Inserting elements into an array
• Access to elements of an array; including their display
• Array copy
• Export and import of arrays
• Conversion: Array ←→ vector
• Sorting the elements of an array

The class array (gb) is the Parent class for each other array class. An array is to be understood as a data container whose elements can be accessed with a numeric key (index).

The class Array (gb) has these properties:

Table 7.4.0.3.1: Properties of the class Array (gb)

The class Array (gb) has basic methods and special methods, but these do not apply to all array classes. The next section introduces and describes the basic methods:

Table 7.4.0.4.4.1: Methods 1 of class Array (gb)

Hints:

• Clear(): Deletes all elements in a one-dimensional array and returns 0. If the array is multidimensional (–> chapter 7.4.4), then the values of all array elements - depending on the data type - are set to the default value.
• Remove (i, k): Deletes the element with the specified index=i from the array. If the optional parameter Length=k is also set to k>0, k elements are deleted from the array starting with array[i]. If k is negative, then all elements array[i.. Max] are removed in the array.
• Resize(s): With Array. resize (s) you set the number of elements in an array to the number=s. The number of elements in the array is thus reduced or increased. Either excess elements are removed from the end or additional elements are added - depending on the type of array with their default value for native arrays (–> chapter 7.4.3.1).

In the following table,' array type' always stands for the data type of an element in the array.

Tabel 7.4.0.4.4.2: Methods 2 of class Array

Gambas has a predefined array class for each native data type –> chapter 7.4.3.1. the name of these classes is the name of the data type followed by square brackets[].

Boolean[], Byte[], Short[], Integer[], Long[], Single[], Float[], Date[], String[], Object[], Pointer[] und Variant[]

Please note the following notes, as all arrays do not have all and other methods:

• For all (native) arrays - except Variant[] - there is the method Sort ([Mode As Integer]).
• Only string[] has the method Join ([ Separator As String, Escape As String]).
• For the native arrays Boolean[], Byte[], Short[], Integer[], Long[], Long[], Single[], Float[], Date[], Pointer[], there are two methods Read (stream as stream[, start as integer, length as integer] and Write (stream as stream[, start as integer, length as integer]).
• The ToString method ([ Start As Integer, Length As Integer]) knows only byte[].
• Only for the arrays Object[] you can use the two methods FindByRef (value as object[, start as integer] and ExistByRef (value as object).

Arrays can have these methods in the following table:

Table 7.4.0.5.1: Methods 3 of the class array