sorting by array field

pnoeric

Hi - I think I'm missing something obvious here, but I don't see a way to do this with PHP's numerous array sort options.

Here's my source array:

$new[0] = array('a'=>5, 'b'=>3, 'c'=>7)
$new[1] = array('a'=>5, 'b'=>6, 'c'=>7)
$new[2] = array('a'=>5, 'b'=>1, 'c'=>7)

I want to sort the $new[] array on the value of 'b'... but I don't anything else to change, just the order of $new[].

Any tips, advice, or "duh, try this" suggestions would be appreciated...

thanks
Eric

sp0rk

Check out the comments to the online manual for sort.

http://www.php.net/manual/en/function.sort.php

The array_qsort2-function posted on 18-Apr-2001 has saved my sanity many times over.

pnoeric

I'll check it out, thanks...!

Josh

I took a look at the user submited array_qsort2 function, and there is a far easier method of doing the same thing using the usort function. Here is an example for you to try:

	function usort_descending($array1, $array2)
	{
		if($array1["b"] == $array2["b"])
			return 0;
		elseif($array1["b"] > $array2["b"])
			return -1;
		else
			return 1;
	}

function usort_ascending($array1, $array2)
{
	if($array1["b"] == $array2["b"])
		return 0;
	elseif($array1["b"] > $array2["b"])
		return 1;
	else
		return -1;
}

$new[0] = array('a'=>5, 'b'=>3, 'c'=>7) ;
$new[1] = array('a'=>5, 'b'=>6, 'c'=>7) ;
$new[2] = array('a'=>5, 'b'=>1, 'c'=>7) ;

usort($new, "usort_descending"); // Sorts by $new[][b] descending
usort($new,"usort_ascending"); // Sorts by $new[][b] ascending

Give it a try... smaller, easier to understand code is always best 🙂