OPTION _EXPLICITARRAY - mkilgore/QB64pe GitHub Wiki

OPTION _EXPLICITARRAY instructs the compiler to require arrays be declared with DIM, REDIM or equivalent.

OPTION _EXPLICITARRAY

• Normally statements like x(2) = 3 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: i = 1

• If used, OPTION _EXPLICITARRAY must be the very first statement in your program. No other statements can precede it (except for $NOPREFIX or comment lines started with an apostrophe or REM).
• Do not use OPTION _EXPLICITARRAY in $INCLUDEd modules.

Example: Avoiding simple typos with OPTION _EXPLICITARRAY results shown in the QB64 IDE Status area.

DIM z(5)
z(2) = 3 'All good here, we've explicitly DIMmed our array

y(2) = 3 'This now generates an error

QB64 IDE Status will show: Array 'y' (SINGLE) not defined on line 7

• OPTION _EXPLICIT
• DIM, REDIM
• SHARED
• STATIC