How to determine the first and last iteration in a foreach loop?

Question

The question is simple. I have a foreach loop in my code:

foreach($array as $element) {
    //code
}

In this loop, I want to r

Answer 1

For SQL query generating scripts, or anything that does a different action for the first or last elements, it is much faster (almost twice as fast) to avoid using unneccessary variable checks.

The current accepted solution uses a loop and a check within the loop that will be made every_single_iteration, the correct (fast) way to do this is the following :

$numItems = count($arr);
$i=0;
$firstitem=$arr[0];
$i++;
while($i<$numItems-1){
    $some_item=$arr[$i];
    $i++;
}
$last_item=$arr[$i];
$i++;

A little homemade benchmark showed the following:

test1: 100000 runs of model morg

time: 1869.3430423737 milliseconds

test2: 100000 runs of model if last

time: 3235.6359958649 milliseconds

And it's thus quite clear that the check costs a lot, and of course it gets even worse the more variable checks you add ;)