View source for OPTION BASE

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 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 {{InlineCode}}DIM array(5 TO 10){{InlineCodeEnd}}


{{PageExamples}}
''Example 1:'' Set the default lower bound for array declarations to one.
{{CodeStart}}
{{Cl|OPTION BASE}} 1

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

{{Cl|PRINT}} {{Cl|LBOUND}}(array)
{{CodeEnd}}
{{OutputStart}} 1{{OutputEnd}}


''Example 2:'' Set the default lower bound for array declarations to zero.
{{CodeStart}} '' ''
{{Cl|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.
{{Cl|DIM}} array(2, 10 to 15) {{Cl|AS}} {{Cl|INTEGER}}

{{Cl|PRINT}} {{Cl|LBOUND}}(array, 1)
{{Cl|PRINT}} {{Cl|LBOUND}}(array, 2)
{{CodeEnd}}
{{OutputStart}} 0
 10
{{OutputEnd}}


{{PageSeeAlso}}
* [[Arrays]], [[LBOUND]], [[UBOUND]]
* [[DIM]], [[REDIM]], [[STATIC]], [[COMMON]]


{{PageNavigation}}