i was reading a book when i came across this piece of text that i didnt understand . please explain
auto int i;
static int j;
register int k;
extern int l;
the text says that the first three are definitions whereas the last one is a declaration.how is that??
See answer to this following question, there can be no greater answer other than this. You will know everything about extern keyword.
[What are extern variables in C][1]
Hope it helps, Best Luck 
[1]: c++ - How do I use extern to share variables between source files? - Stack Overflow
Ohh you are fast 
hehehe…