no error displays if varible re-difined

if you paint a wall blue twice is is any different from if you paint it blue once?

"if you paint a wall blue twice is is any different from if you paint it blue once?"

Like to know what paint you use. Whenever I paint, I put on two coats to stop the old color showing through.

Glad programming doesn't exhibit the same effect ;)

char xxxx;
char xxxx;//no error displays if varible re-difined

An actual redefinition would be treated as an error, but the above isn't one.

You want to get out your C textbook and read up on the difference between declarations and definitions. Pay special attention to the topic of "tentative definitions".