The statement " ++IF <constant expression> " evaluates the specified expression and compiles the following statements if the expression is equivalent to TRUE. Constant expressions are a subset of regular BASIC expressions, made up only of defined symbols (constants) and literals (i.e. no variables), and a limited set of pre-defined functions and operators:

• All arithmetic operators (+,-,/,*,**,^,MOD)

• All logical operators (AND, OR, NOT)

• Comparison operators (<, >, <=, >=, ==, <>, #)

• All bitwise operators (AND, OR, NOT, NOR, XOR)

• Arithmetic functions: int(),fix(),abs(),min,max

• Scientific functions: exp(),sgn(),sqr(),sin(),cos(),tan(),atn(),fact()

• String functions: +,left(),mid(),right(),[a,b],len(),instr(),asc(),chr(), str(),val(),rtrim(),edit(),strip(),pad(0

• File functions: lookup()

 

++IF APPVER > 3

++IF CUSTOM$ = "MR. BIG"

++IF (APPVER > 3) AND (LOOKUP("xyz.bsi") # 0)