====== #undef ======

===== Description =====
With the # undef a macro can be overridden.\\
Status "defined" or "undefined" is an important characteristic of an identifier, regardless of its actual definition.\\
The # ifdef and # ifndef can be used to check whether an identifier is currently defined or not.\\

Syntax\\
<code c>
#undef macro_name
</code>

===== c undef example =====
<code c>
  #include <stdio.h>

  int main(void)
  {
    #define TESTDEFINE 1
      printf("%d\n", TESTDEFINE);

    #undef TESTDEFINE

    #define TESTDEFINE 42
      printf("%d\n", TESTDEFINE);

    return 0;
  }
</code>

=== output ===
     1
     42