sorting arrays

[rakennedy75]

I have an array of emails that I want to sort but I want to sort them by the email client. Example:

$email_array = array ("[e-mail]", "[e-mail]", "[e-mail]");

So know if I was to sort this and get all the place.com emails together so when I send them to the server to email, they will be sent all at once by the email box name (place.com).

I have been told it is less work for the server and faster for the emails to be sent like this. Imagine you have a 200 yahoo.coms and 300 aol.coms, etc... well, I would think this would start to take its toll on the servers.

Any comments on how to do this or approach this would be wonderful.
Hopefully my explanation is clear, if not, please let me know.
Thanks for your time

[laserlight]

hmm... for some reason I could not find a regex function to do this sort, though I thought there was one.

Anyway, I wrote a simple function for you.
You might want to re-implement it using some sorting algorithm, say quicksort, and do the extra swapping on the fly rather than in 2 loops:

function sortByDomain($email_array) {
	//declare name and domain arrays
	$names = array();
	$domains = array();
	//separate emails into name@domain
	foreach ($email_array as $key => $value) {
		$temp = explode('@', $value);
		$names[$key] = $temp[0];
		$domains[$key] = $temp[1];
	}
	//now sort the domain array
	//we maintain index association for the name array
	asort($domains);
	//let's join the name and domain back
	$emails = array();
	foreach ($domains as $key => $value) {
		$emails[] = $names[$key] . '@' . $value;
	}
	return $emails;
}

[Weedpacket]

If you can work out how to compare two addresses and decide which one should come before the other, then that's the hard work done.

function compare_two_addresses($a,$b)
{ // Something based on laserlight's
  // use of explode() will work here
}

After that it's just a matter of calling [man]usort[/man].

[drawmack]

weebpacket's method is interesting

<?php
function cmpTwoAddys($a,$b) {
    //split the addresses into arrays on the @ sign
    $addy_one = explode('@',$a);
    $addy_two = explode('@',$b);


//create an array to look at the hosts, in a case insesitive manner.
$hosts = array(
    strtolower($addy_one[1]),
    strtolower($addhy_two[1]));

//if $a & $b are equal
if(count(array_unique($hosts)) == 1) {return 0;}

$hosts_2 = $hosts;
sort($hosts_2);

 //if $a < $ b
 if($hosts_2[0] == $hosts[0]) {return -1;}
 if $a > $ b
 else {return 1;}
} //end cmpTwoAddys

this code is untested but should be close to what you need.