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qb64/internal/help/OPTION__EXPLICITARRAY.txt
2021-10-09 14:06:54 -03:00

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{{DISPLAYTITLE:OPTION _EXPLICITARRAY}}
[[OPTION _EXPLICITARRAY]] instructs the compiler to require arrays be declared with [[DIM]], [[REDIM]] or equivalent.
{{PageSyntax}}
: [[OPTION _EXPLICITARRAY]]
{{PageDescription}}
* Normally statements like {{InlineCode}}x(2) = 3{{InlineCodeEnd}} will implicitly create an array x(). [[OPTION _EXPLICITARRAY]] requires a preceding declaration for the array, helping to catch mistyped array and function names.
* Unlike [[OPTION _EXPLICIT]], simple variables can still be used without a declaration. Example: {{InlineCode}}i = 1{{InlineCodeEnd}}
{{PageErrors}}
* It's not advisable to use [[OPTION _EXPLICITARRAY]] in [[$INCLUDE]]d modules.
{{PageExamples}}
''Example:'' Avoiding simple typos with [[OPTION _EXPLICITARRAY]] results shown in the QB64 IDE Status area.
{{CodeStart}}{{Cl|OPTION _EXPLICITARRAY}}
x = 1 'This is fine, it's not an array so not affected
{{Cl|DIM}} z(5)
z(2) = 3 'All good here, we've explicitly DIMmed our array
y(2) = 3 'This now generates an error
{{CodeEnd}}
''QB64 IDE Status will show:''
'''Array 'y' (SINGLE) not defined on line 7'''
{{PageSeeAlso}}
* [[OPTION _EXPLICIT]]
* [[DIM]], [[REDIM]]
* [[SHARED]]
* [[STATIC]]
{{PageNavigation}}