how to remove duplicate elements from an array of arrays in PHP

Question

"2017-08-31":["5948a0dd21146a43fdcfef5a","5948a0dd21146a43fdcfef5a"]
"2017-08-22":["5948a0dd21146a43fdcfef5a"]
"2017-08-09":["59461ceae6179b19403c6a19","59461ceae6179b19403c6a19"]
"2017-08-08":["59461ceae6179b19403c6a19","59461ceae6179b19403c6a19"]

I have an array like this, key is a date and multiple value associated with that date, but I need unique value with that key.how to do that ? I've tried with array_unique but no luck!

As above, you need to define your problem better to get help - it looks like you could just take the 1st result from all the subarrays, but that might not be the case - you need to clarify — Steve, Sep 06 '17 at 09:38
`"2017-08-31":["5948a0dd21146a43fdcfef5a"] "2017-08-22":["5948a0dd21146a43fdcfef5a"] "2017-08-09":["59461ceae6179b19403c6a19"] "2017-08-08":["59461ceae6179b19403c6a19"]` @Neodan — FightForJustice, Sep 06 '17 at 09:38
so each data key will contain a single element array? Will your source array always contain duplicates, or could a date key contain an array with non duplicate values? If so, which value gets kept? Or perhaps your output could contain multiple elements per key if they are unique? — Steve, Sep 06 '17 at 09:41

score 4 · Accepted Answer · answered Sep 06 '17 at 09:43

Just use array_map and array_unique together.

<?php
$a = json_decode('{"2017-08-31":["5948a0dd21146a43fdcfef5a","5948a0dd21146a43fdcfef5a"],
                   "2017-08-22":["5948a0dd21146a43fdcfef5a"],
                   "2017-08-09":["59461ceae6179b19403c6a19","59461ceae6179b19403c6a19"],
                   "2017-08-08":["59461ceae6179b19403c6a19","59461ceae6179b19403c6a19"]}', true);

echo json_encode(array_map("array_unique", $a));

score 2 · Answer 2 · answered Sep 06 '17 at 09:43

2

$array = your array   
$array = array_map(function($val){return array_unique($val);}, $array);

answered Sep 06 '17 at 09:43

Muhammed Imran Hussain

2,057
16
24

score 1 · Answer 3 · answered Sep 06 '17 at 09:42

1

You better do this using SQL if it's possible. Otherwise, you can try this:

$array = array_unique($array, SORT_REGULAR);

answered Sep 06 '17 at 09:42

Mohamed Chaawa

918
1
9
23

1

Works like magic! – Joel Hernandez Aug 13 '19 at 17:01

how to remove duplicate elements from an array of arrays in PHP

3 Answers3