Duplicates in Arrays

ChetUbetcha

Yes, I've tried array_count_values, but can't figure this one out. I have an array that has a lot of duplicates in it. I want to find the ones that are duplicates so I can run code to find the difference between the two based on certain fields they each contain. So, if it's a duplicate, check to see if the dates in that array are different or the same. If it does not have a duplicate, move on to the next one.

ChetUbetcha

I figured I'd try building an ALL array and then a DISTINCT array, then run an array_diff. I was using array_diff before, but this one is only outputting Array(). Hmmm....

scrupul0us

can you show us an example of your array structure

ChetUbetcha

Like this? Array ( [0] => PC-0929 [1] => PC-0928 [2] => PC-0927 [3] => PC-0926 [4] => CJIS-0123 [5] => PC-0924 [6] => PC-0923. I didn't order the items. That's from the ALL array. Array ( [0] => PC-0929 [1] => PC-0928 [2] => PC-0927 [3] => PC-0926 [4] => CJIS-0123 [5] => PC-0924 was from the DISTINCT array.

I tried

$result = array_diff($list_all_array,$list_unique_array);
print_r($result);

But only came up with Array () I even swapped the two to see if there was a difference. What gives with that?

scrupul0us

so, lets say you have two or more array values that are the same, you are doing your investigation/checking outside the array on some other data set/structure?

ChetUbetcha

Not outside. Just running the arrays all on one page. My simple mind came up with the (probably unsuccessful) idea that if I generated an array of all the items, then another array with the distinct items, I could run a compare right after that and see what the difference was. Of course, I think my logic is okay but really doesn't work. Maybe the Array() answer is because it is showing there is nothing to report after the array_diff?

scrupul0us

also, to get a list of values that are duplicated you can try:

$checkKeysUniqueComparison = create_function('$value','if ($value > 1) return true;');
$result = array_keys (array_filter (array_count_values($array), $checkKeysUniqueComparison));

Given:
$array = array ("a", "b", "a", "b", "x", "y", "z", "x");

Result:
Array([0] => a [1] => b [2] => x)

taken from:
http://us2.php.net/manual/en/function.array-unique.php

ChetUbetcha

Well, I tried your idea and changed $array to my name $list_all_array.

$checkKeysUniqueComparison = create_function('$value','if ($value > 1) return true;');
$result = array_keys (array_filter (array_count_values($list_all_array), $checkKeysUniqueComparison));

I don't rcv any errors, but I don't rcv any data either. There are roughly 28,000 items in the array and I know more than half of them are duplicates. I even went here http://www.php.net/manual/es/function.array-unique.php#28892 to see the example explained just in case I was messing something up.

scrupul0us

it may have something todo with it using array_keys and your array not being keyed

try removing array_keys() from the second line and see what you get

ChetUbetcha

It still runs without array_keys(), but I still get nothing for results. I ordered the array to make sure there were duplicates and so I could show I wasn't crazy...

Array ( [0] => 1-5120-B01 [1] => 1-5120-B01 [2] => 1-5120-B10 [3] => 1-5120-B10 [4] => 1-5120-C20 [5] => 1-5120-C20 [6] => 1-5120-C99 [7] => 1-5120-C99 [8] => CJIS [9] => CJIS [10] => CJIS-0000 [11] => CJIS-0000 [12] => CJIS-0001 [13] => CJIS-0001 [14] => CJIS-0002 [15] => CJIS-0002 [16] => CJIS-0003 [17] => CJIS-0003...