Computer Programming Concepts and Visual Basic David I. Schneider

3. The two arrays in Example 3 are referred to as parallel arrays because subscripted
variables having the same subscript are related.
4. The integers m and n in the statement Dim arrayName(m To n) As varType can
be positive, negative, or zero. The only restriction is that m cannot be greater
than n. The same holds true for ReDim statements.
5. Until a value is assigned to an element of an array, the element has its default
value. Numeric variables have a default value of 0, and string variables have the
default value “”, the empty string.
6. The statement Dim arrayName(0 To n) As varType can be replaced by the statement
Dim arrayName(n) As varType. The same holds for the ReDim statement.
7. An array whose range has been specified by a ReDim statement is said to be
dynamic. If array1() is a dynamic array, and array2() is another array of the
same data type (such as String), then the line
array1 = array2
makes array1() an exact duplicate of array2(). It will have the same size and
contain the same information. This feature was added in Visual Basic 6.0.
8. A dynamic array can be resized with another ReDim statement. However, the
resized array loses all its information. If it is resized with the words ReDim
Preserve, as much information as possible will be retained.
6.2 USING ARRAYS
This section considers three aspects of the use of arrays: processing ordered arrays, reading
part of an array, and passing arrays to procedures.
■ ORDERED ARRAYS
An array is said to be ordered if its values are in either ascending or descending order. The
following arrays illustrate the different types of ordered and unordered arrays. In an ascending
ordered array, the value of each element is less than or equal to the value of the next element.
That is,
[each element] ≤ [next element].
For string arrays, the ANSI table is used to evaluate the “less than or equal to” condition.
Using Arrays 171