expected unqualified id before '\0'

I tried following things b开发者_Go百科ut I am getting the error

typedef '\0' DEFAULT_VALUE;   

Error: expected unqalified id before '\0'`

typedef NULL DEFAULT_VALUE;   

Error: expected unqalified id before __null

what I am doing wrong here?

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The general syntax of a typedef is:

typedef existing_type new_type_name ;

Since '\0' and NULL are not existing types you get the error.

Since you want define constants you can use the const as:

const int DEFAULT_VALUE = '\0';

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The keyword typedef defines synonym for existing type. Neither \0 nor NULL are type. May be you want something as follows:

#define DEFAULT_VALUE NULL