To i++ or to ++i…
Ξ April 25th, 2009 | → 0 Comments |
∇ Programming | ∇ C++, Language, Programming, Puzzle |
The question is very simple. When writing a for loop, such as the following one
for( int i = 0; i < 10, /* increment i */ )
Between i++ or ++i, which increment operator would you use? Why?
If you choose the answer “It’s the same! Both increment i.“, or if your answer was “I have always used i++, because /* some place ulterior reason here, like ‘I’m programming in c++ and not in ++c’ */“, then your might thing improving your c++ knowledge a little bit. 
I just learned it myself, so I’ll share. In fact, it’s so simple it makes me wonder how many of these small details are missed every time my C++ source code lines are incremented. The best increment operator to be used in the pre-increment.
Why? Because it avoids the creation of a temporary variable. Post-increment (i++) has to create a temporary variable to store the return result (that you won’t be using), while incrementing this as expected. Pre-increment simply increments the value of this and returns.
So, systematically using ++i, instead of i++, should improve your runtime performance - even if so slightly.
