Programming Tip Of The Day #2 – Difference Between i++ and ++i04 Dec 2009
To some, this should seem a bit obvious and if I am insulting your intelligence by discussing it, I am sorry. But, one of the main reasons I want to discuss this topic is, I was asked this question in a job interview for Lockheed Martin.
What is the difference between i++ and ++i?
The answer is actually quite simple.
i++ first evaluates the value of i and then increments it
++i increments the value of i and then evaluates it
Here is a brief example to demonstrate what I mean.
// Example: i++ $i = 5; echo "The value of i is " . $i++ ; // Output "The value of i is 5" // i = 6 // Example: ++i $i = 5; echo "The value of i is " . ++$i; // Output "The value of i is 6" // i = 6
So, now if you are ever asked about this in an interview, you will have a response.