increment decrement- controvresy Why?

what is the value of cout<<++a + ++a + ++a if a=5;
what is the value of b = ++a + ++a + ++a if a=5; cout<<b;
See the difference . can any body tell why it is ? Pls help me.

 

first one 21
second one 18
is it correct
if it is then i will go with explanation

 

the value of b=24;
a is preincremented 3 times.hence the value of a=8.
then those get added 8+8+8=24;
the value is same in both cases ;

 

k i have mistaken
what u have said is true for second case
but for first one it will be 21
please check it out

 

we executed the statement(manually). it gave the same result i.e., 21. Maybe you could ask the complier to do it either c/c++