P2034

Code

P2034

Message

NULL can only be assigned to a REF_TO type

This error occurs when NULL is assigned to a variable that is not a REF_TO type. NULL represents an empty reference and can only be used with reference types.

Example

The following code will generate error P2034:

PROGRAM Main
    VAR
        x : INT;
    END_VAR

    x := NULL;  (* Error: NULL can only be assigned to REF_TO types *)
END_PROGRAM

To fix this error, ensure the target variable is a reference type:

PROGRAM Main
    VAR
        x : REF_TO INT;
    END_VAR

    x := NULL;  (* Correct: x is REF_TO INT *)
END_PROGRAM

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