OPTION _EXPLICITARRAY

OPTION _EXPLICITARRAY instructs the compiler to require arrays to be properly dimensioned with DIM or REDIM before first use. However, it doesn't require regular variables to be declared.

Syntax

OPTION _EXPLICITARRAY

Description

• Normally statements like x(2) = 3 will implicitly create an array x(). OPTION _EXPLICITARRAY requires proper dimensioning 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

Errors

• 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.

Examples

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

OPTION _EXPLICITARRAY x = 1 'This is fine, it's not an array so not affected 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

See also

• OPTION _EXPLICIT
• DIM, REDIM
• SHARED
• STATIC

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