OPTION _EXPLICIT - mkilgore/QB64pe GitHub Wiki

OPTION _EXPLICIT instructs the compiler to require variable declaration with DIM, REDIM or an equivalent statement.

OPTION _EXPLICIT

• With OPTION _EXPLICIT you can avoid typos by having QB64 immediately warn in the Status area of new variables used without previous declaration.
• Enable OPTION _EXPLICIT temporarily even if a program source file doesn't contain the directive by specifying the -e switch when compiling via command line (qb64 -c file.bas -e).

• If used, OPTION _EXPLICIT 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 _EXPLICIT in $INCLUDEd modules.

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

DIM myVariable AS INTEGER

myVariable = 5

PRINT myVariabe

QB64 IDE Status will show: Variable 'myVariabe' (SINGLE) not defined on line 4

• OPTION _EXPLICITARRAY
• DIM, REDIM
• SHARED
• STATIC