How to filter the Unique Objects in this PHP array object

Question

I have an array of objects generated from server side which I want to filter for duplicates in PHP ...

Below is the generated array

array:5 [▼
  0 => {#204 ▼
    +"category_name": "Fashion"
    +"category_id": "fashion"
  }
  1 => {#205 ▼
    +"category_name": "Fashion"
    +"category_id": "fashion"
  }
  2 => {#209 ▼
    +"category_name": "Shirts"
    +"category_id": "shirts"
  }
  3 => {#210 ▼
    +"category_name": "Health"
    +"category_id": "health"
  }
  4 => {#211 ▼
    +"category_name": "Shirts"
    +"category_id": "shirts"
  }
]

Here Array 0 and 1, Array 2 and Array 4 have same values, how to filter and get only a single values for the duplicate in the existing array or a newly generated array.

Doomd · Answer 1 · 2021-01-10T21:30:42.210

By looking at your data, it appears that you could filter through your array of objects by comparing the uniqueness of ONE property. If that's the case, when dealing with very large arrays, it's much more efficient to compare a single property instead of essentially turning each object into a string and doing a comparison that way.

Here's a function that should return objects that are unique by one property:

function returnUniqueProperty($array,$property) {
  $tempArray = array_unique(array_column($array, $property));
  $moreUniqueArray = array_values(array_intersect_key($array, $tempArray));
  return $moreUniqueArray;
}

$uniqueObjectsById = returnUniqueProperty($yourArray, 'category_id');

Explanation:

We pass in to our function, the array, and the property name of column you want to perform the "uniqueness" comparison with.
Then we use php's array_column() function to return an array of only the property we want to compare. This array will have the same index values as our original array. php.net
Then we use array_unique() to filter out any duplicates in our temporary array. Crucially, by default, this will remove duplicates, but preserve the original index positions of each unique property value. php.net
Now, we just have to match the index positions of our unique array of property values with our original array's index values, with array_intersect_key(). php.net
Finally, we want to "compact" our array, so we array_values(), which returns a new array with a fresh index in numerical order. php.net

score 1 · Answer 2 · edited Nov 22 '17 at 19:31

1

Use array_unique() PHP function:

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

edited Nov 22 '17 at 19:31

Layke

51,422
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answered Aug 14 '16 at 09:10

Vicente Olivert Riera

990
7
14

1

Cant use array_unique : Error: Object of class stdClass could not be converted to string – ChanX Aug 14 '16 at 09:14
Those objects that you put into the array, make sure they implement a `__toString()` method. – Vicente Olivert Riera Aug 14 '16 at 09:16
2

After converting object to array and using `array_unique(,SORT_REGULAR)` it's working – ChanX Aug 14 '16 at 09:17
But i want to make the value take new keys instead of inheriting the old keys – ChanX Aug 14 '16 at 09:21
And which keys do you want to have? – Vicente Olivert Riera Aug 14 '16 at 09:23
when its filtered it returned the index as 0, 2 , 3 whereas i want to get the new array as 0, 1, 2 – ChanX Aug 14 '16 at 09:28
1

Loop though the array and push every element to a new array, this way the keys will start from 0 and will be consecutive. – Vicente Olivert Riera Aug 14 '16 at 09:31

score 1 · Answer 3 · answered Feb 24 '20 at 09:59

1

I have the same problem. After adding SORT_REGULAR in array_unique then it works for me.

array_unique($objectArray, SORT_REGULAR)

answered Feb 24 '20 at 09:59

Umar Tariq

1,191
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score 1 · Answer 4 · answered Nov 05 '21 at 12:13

//comment start:: Dont change "returnUniqueProperty" function
function returnUniqueProperty($array,$property) {
  $tempArray = array_unique(array_column($array, $property));
  $moreUniqueArray = array_values(array_intersect_key($array, $tempArray));
  return $moreUniqueArray;
}
//comment end::

$uniqueObjectsById = returnUniqueProperty($yourArray, 'category_id');
// "yourArray" replace with your arrayname
//"category_id" is property to filter:: in your case "category_id"

How to filter the Unique Objects in this PHP array object

4 Answers4

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