OPTION BASE: Difference between revisions

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(Created page with "The OPTION BASE statement is used to set the default lower bound of arrays. {{PageSyntax}} : OPTION BASE {0|1} {{PageDescription}} * This statement affects array declarations where the lower bound of a dimension is not specified. * When used, OPTION BASE must come before any array declarations (DIM) to be affected. * By default, the lower bound for arrays is zero, and may be changed to one using the statement. * Otherwise, arrays will be dimensioned f...")
 
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''Example 2:'' Set the default lower bound for array declarations to zero.
''Example 2:'' Set the default lower bound for array declarations to zero.
{{CodeStart}} '' ''
{{CodeStart}}
{{Cl|OPTION BASE}} 0
{{Cl|OPTION BASE}} 0


' Declare an 18-element two-dimensional array with element indexes of zero through two  
' Declare an 18-element two-dimensional array with element indexes of zero through two
' for the first dimension, and 10 through 15 for the second dimension.
' for the first dimension, and 10 through 15 for the second dimension.
{{Cl|DIM}} array(2, 10 to 15) {{Cl|AS}} {{Cl|INTEGER}}
{{Cl|DIM}} array(2, 10 to 15) {{Cl|AS}} {{Cl|INTEGER}}

Latest revision as of 02:15, 23 January 2023

The OPTION BASE statement is used to set the default lower bound of arrays.


Syntax

OPTION BASE {0|1}


Description

  • This statement affects array declarations where the lower bound of a dimension is not specified.
  • When used, OPTION BASE must come before any array declarations (DIM) to be affected.
  • By default, the lower bound for arrays is zero, and may be changed to one using the statement.
  • Otherwise, arrays will be dimensioned from element 0 if you DIM just the upper bounds.
  • You can also set other array boundaries by using TO in the DIM declaration such as DIM array(5 TO 10)


Examples

Example 1: Set the default lower bound for array declarations to one.

OPTION BASE 1

' Declare a 5-element one-dimensional array with element indexes of one through five.
DIM array(5) AS INTEGER

PRINT LBOUND(array)
 1


Example 2: Set the default lower bound for array declarations to zero.

OPTION BASE 0

' Declare an 18-element two-dimensional array with element indexes of zero through two
' for the first dimension, and 10 through 15 for the second dimension.
DIM array(2, 10 to 15) AS INTEGER

PRINT LBOUND(array, 1)
PRINT LBOUND(array, 2)
 0
 10


See also



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