[SOLVED] Error: Forward declaration not solved lazarus / 39-Graphics ---------------------------------------------------------------------- avv210 · 2021-12-24 13:03 Hi, so I wanted to create my steganography software. I created a function ReverseBits(const bits:String): String; And I am getting an error like in the title of this topic. I cannot attach because the project file is too big. GitHub project link: https://github.com/AlphaByte- RedTeam/PascalSteg/tree/development  -> on branch development Feel free to contribute ---------------------------------------------------------------------- marcov · 2021-12-24 13:07 There is a reversebits() in the class declaration, but no implementation. In Lazarus, go to the definition of reversebits and press ctrl- shiftt-c ---------------------------------------------------------------------- avv210 · 2021-12-25 13:38 Quote from: marcov on December 24, 2021, 02:07:47 pmThere is a reversebits() in the class declaration, but no implementation. In Lazarus, go to the definition of reversebits and press ctrl- shiftt-c Thank you for the answer. It helps a lot.