php.net |  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login

go to bug id or search bugs for

Bug #79399 array_map preserves keys if array_unique is used before
Submitted: 2020-03-20 16:26 UTC Modified: 2020-03-20 17:05 UTC
From: nemanjac85 at gmail dot com Assigned:
Status: Not a bug Package: Arrays related
PHP Version: 7.3Git-2020-03-20 (Git) OS: Ubuntu 18.04
Private report: No CVE-ID: None
View Developer Edit
Welcome back! If you're the original bug submitter, here's where you can edit the bug or add additional notes.
If you forgot your password, you can retrieve your password here.
Password:
Status:
Package:
Bug Type:
Summary:
From: nemanjac85 at gmail dot com
New email:
PHP Version: OS:

 

 [2020-03-20 16:26 UTC] nemanjac85 at gmail dot com 
Description:
------------
Function array map should produce a new numeric array containing values returned from the callback. This works fine most of the time but apparently if input array_unique is called on input array before calling array_map the new array preserves the numeric indexes.

This further causes issues with json_encode and instead of array of values it encodes the objects with numeric indexes as json object keys. 

Calling array_values before json_encode or array_map solves the issue in userland but I think this breaks the specification of array_map.

Test script:
---------------
https://gist.github.com/n-e-m-a-nj-a/cd5a9a5af281e5a912c60dcc7c18227e

Expected result:
----------------
{
    "product_ids": [
        "2d0f7178-9cec-4dbe-9de2-89005735d595",
        "c45152d2-b6c8-4e8f-a113-c6006dad41d9",
        "dcb4caa4-58a5-424a-a110-cff0f3417a86",
        "f6696454-0d05-4975-b731-1d1201c5de46",
        "7aa45f2e-974c-4340-bf10-72786d554a8b",
        "e3303bfa-36c0-4526-94fb-6a6a0b5a814b",
        "7dfc4796-8784-4918-869d-3bddf0a58d30",
        "638f65f3-2a77-4c74-9abf-4d026a81fd65",
        "cac84617-b5fb-4651-9d40-19ff78ff2e72",
        "1a6c9a25-6f37-4e7a-87de-09c88e5f5a4a",
        "d178d85a-64be-48eb-985d-ddb2901a369b",
        "6fb1bc0a-5fe6-4807-a396-6fe3264c5b49",
        "9843d152-6105-476e-868c-3ca6b7353712",
        "dbb093de-141c-47ca-be91-ad475bb6e69d"
    ]
}

Actual result:
--------------
{
    "product_ids": {
        "0": "2d0f7178-9cec-4dbe-9de2-89005735d595",
        "1": "c45152d2-b6c8-4e8f-a113-c6006dad41d9",
        "2": "dcb4caa4-58a5-424a-a110-cff0f3417a86",
        "3": "f6696454-0d05-4975-b731-1d1201c5de46",
        "4": "7aa45f2e-974c-4340-bf10-72786d554a8b",
        "6": "e3303bfa-36c0-4526-94fb-6a6a0b5a814b",
        "7": "7dfc4796-8784-4918-869d-3bddf0a58d30",
        "8": "638f65f3-2a77-4c74-9abf-4d026a81fd65",
        "9": "cac84617-b5fb-4651-9d40-19ff78ff2e72",
        "10": "1a6c9a25-6f37-4e7a-87de-09c88e5f5a4a",
        "11": "d178d85a-64be-48eb-985d-ddb2901a369b",
        "14": "6fb1bc0a-5fe6-4807-a396-6fe3264c5b49",
        "15": "9843d152-6105-476e-868c-3ca6b7353712",
        "17": "dbb093de-141c-47ca-be91-ad475bb6e69d"
    }
}

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2020-03-20 16:31 UTC] peehaa@php.net
-Status: Open +Status: Not a bug
 [2020-03-20 16:31 UTC] peehaa@php.net 
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

> The returned array will preserve the keys of the array argument if and only if exactly one array is passed.
 [2020-03-20 17:05 UTC] requinix@php.net 
Would the behavior make more sense if I pointed out that array_unique also preserves keys?
 
PHP Copyright © 2001-2025 The PHP Group
All rights reserved. 		Last updated: Tue Mar 11 06:01:29 2025 UTC