Tham khảo tài liệu 'autoit help part 109', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Example If Not IsDeclared a then MsgBox 0 a is NOT declared a has never been assigned EndIf a 1 If IsDeclared a then MsgBox 0 a IS declared due to previous a 1 assignment EndIf Function Reference IsDllStruct Checks if a variable is a DllStruct type. IsDllStruct variable Parameters variable The variable expression to check. Return Value Success Returns 1. Failure Returns 0 if expression is not DllStruct type as return by DllStructCreate. Remarks None. Related DllStructCreate Example struct DllStructCreate char 256 x IsDllStruct struct Function Reference IsFloat Checks if a variable or expression is a float-type. IsFloat variable Parameters variable The variable or expression to check. Return Value Success Returns 1. Failure Returns 0 if expression is not float type. Remarks See examples. Related IsArray IsInt IsString IsNumber IsBool IsHWnd StringIsFloat Example IsFloat returns 1 IsFloat returns 0 since value is integer 3 IsFloat 1 2 - 5 returns 1 IsFloat returns 0 since 1500 IsFloat returns 0 since is a string Function Reference IsHWnd Checks if a variable s base type is a pointer and window handle. IsHWnd variable Parameters variable The variable expression to check. Return Value Success Returns 1 if the expression is a pointer type AND a valid window handle. Failure Returns 0 if expression is not a pointer OR not a valid window handle. .