Can I display the value of an enum with printf

Question

Is there a one-liner that lets me output the current value of an enum

User · Answer

The correct answer to this has already been given: no, you can't give the name of an enum, only it's value.

Nevertheless, just for fun, this will give you an enum and a lookup-table all in one and give you a means of printing it by name:

main.c:

#include "Enum.h"

CreateEnum(
        EnumerationName,
        ENUMValue1,
        ENUMValue2,
        ENUMValue3);

int main(void)
{
    int i;
    EnumerationName EnumInstance = ENUMValue1;

    /* Prints "ENUMValue1" */
    PrintEnumValue(EnumerationName, EnumInstance);

    /* Prints:
     * ENUMValue1
     * ENUMValue2
     * ENUMValue3
     */
    for (i=0;i<3;i++)
    {
        PrintEnumValue(EnumerationName, i);
    }
    return 0;
}

Enum.h:

#include <stdio.h>
#include <string.h>

#ifdef NDEBUG
#define CreateEnum(name,...) \
    typedef enum \
    { \
        __VA_ARGS__ \
    } name;
#define PrintEnumValue(name,value)
#else
#define CreateEnum(name,...) \
    typedef enum \
    { \
        __VA_ARGS__ \
    } name; \
    const char Lookup##name[] = \
        #__VA_ARGS__;
#define PrintEnumValue(name, value) print_enum_value(Lookup##name, value)
void print_enum_value(const char *lookup, int value);
#endif

Enum.c

#include "Enum.h"

#ifndef NDEBUG
void print_enum_value(const char *lookup, int value)
{
    char *lookup_copy;
    int lookup_length;
    char *pch;

    lookup_length = strlen(lookup);
    lookup_copy = malloc((1+lookup_length)*sizeof(char));
    strcpy(lookup_copy, lookup);

    pch = strtok(lookup_copy," ,");
    while (pch != NULL)
    {
        if (value == 0)
        {
            printf("%s\n",pch);
            break;
        }
        else
        {
            pch = strtok(NULL, " ,.-");
            value--;
        }
    }

    free(lookup_copy);
}
#endif

Disclaimer: don't do this.

User · Answer

Some dude has come up with a smart preprocessor idea in this post  Easy way to use variables of enum types as string in C

User · Answer

I had the same problem    I had to print the color of the nodes where the color was  enum col   WHITE  GRAY  BLACK    and the node  typedef struct Node   col color      I tried to print node- gt color with printf   s n   node- gt color   but all I got on the screen was  null  n   The answer bmargulies gave almost solved the problem   So my final solution is   static char  enumStrings       WHITE    GRAY    BLACK    printf   s n   enumStrings node- gt color

User · Answer

As a string  no  As an integer   d   Unless you count   static char  enumStrings          filler 0 s to get to the first value                                     enum0    enum1                                      filler for hole in the middle   0                                    enum2    enum3                 printf  The value is  s n   enumStrings thevalue      This won t work for something like an enum of bit masks  At that point  you need a hash table or some other more elaborate data structure

User · Answer

enum A   foo  bar   a  a   foo  printf    d   a         see comments below

User · Answer

enum MyEnum    A ENUM VALUE 0     B ENUM VALUE     C ENUM VALUE      int main      printf  My enum Value    d n    int C ENUM VALUE    return 0      You have just to cast enum to int   Output   My enum Value   2

[c] Can I display the value of an enum with printf()?

Examples related to c

Examples related to printf

Examples related to enums