Basic Stuff

[aad1986]

Hello,

i am doing my undergraduation....one of my friends said pre increment/decrement is more efficient in implementaion than post increment/decrement...but when i asked him the explanation he said he just heard it(??????!!!!!!!!)...but i dont think efficiency is related to the order of execution if its just a single line like:

++x;
(or)
x++;

could any one pls say whether it is a valid argument or its just a gag...sorry if its too elementary....

thank you

[SuperKoko]

but i dont think efficiency is related to the order of execution if its just a single line like:
++x;
(or)
x++;

For basic types, there's no difference between these two statements.

For compound iterators of complex objects such as std:eque, pre-increment might sometimes be slightly faster than post-increment due to the fact that it saves a temporary that the compiler doesn't optimize out.

For a very good compiler, there should be no difference.

Anyway, for basic types, even with a BAD compiler, there's no speed difference.

could any one pls say whether it is a valid argument or its just a gag...sorry if its too elementary....

It's wiser to think that it's a gag. Making difference between those two constructs is a path to inefficient coding: When a programmer is concerned with pseudo-micro-optimizations, 50% of the time he decreases performances, and in every case, he never gives any big performance boost to his programs.

In the same set of gags, there are recurring questions about what iteration statement (while, for and do-while) has the best performance. All of them perform identically at negligible random differences.