Turn array into nested array using nested loops in php

Question

I am building comments for CMS. I have the following data structure:

$comments=[
[comment_id=>1,...,comment_repay_to=>null],
[comment_id=>2,...,comment_repay_to=>1],
[comment_id=>3,...,comment_repay_to=>2],
[comment_id=>4,...,comment_repay_to=>null]
];

I want to turn into:

$comments=[
    [
        'comment'=>[comment_id=>1,...,comment_repay_to=>null],
        'children'=>[
                [
                        'comment'=>[comment_id=>2,...,comment_repay_to=>1],
                        'children'=>[...]
                ],
        ],
        'comment'=>[comment_id=>4,...,comment_repay_to=>null],
    ],
];

I have written the following incomplete code. I am stuck in loops.

$arr=[];
    $level=0;
    foreach ($comments as $comment){
        if($comment->comment_replay_to==null){
            $temp_comment=$comment;
            $temp_arr=[
                'comment'=>$comment,
                'children'=>[]
            ];
            $level++;
            while($level>0){

            }
        }
    }

Any help would be highly appreciated. Thanks.

Edit: I got the answer on this link:https://books.google.com.pk/books?id=xHc5DwAAQBAJ&pg=PA109&lpg=PA109&dq=recursive+display+threaded+comments&source=bl&ots=b2PLCOnMnX&sig=ACfU3U1Jy6iUh-qeOZlPfgz3QnIAFlitLA&hl=en&sa=X&ved=2ahUKEwjK86Sm6PjjAhXsA2MBHfORAdsQ6AEwEnoECAkQAQ#v=onepage&q&f=false

Will parent always come before child in the initial array?

nice_dev
– nice_dev

2019-08-09 15:51:23 +00:00
Commented Aug 9, 2019 at 15:51 — nice_dev
– nice_dev, Commented Aug 9, 2019 at 15:51

arkascha · Accepted Answer · 2019-08-09 17:43:05Z

1

Not exactly beautiful, but should point you into the right direction:

<?php

// process input in reverse order
$input = array_reverse([
    ['id' => 1, 'message' => 'A', 'parent' => null],
    ['id' => 2, 'message' => 'B', 'parent' => 1],
    ['id' => 3, 'message' => 'C', 'parent' => 2],
    ['id' => 4, 'message' => 'D', 'parent' => null]
]);

// use 'id' as actual key for the entry, saves a lot of hassle
array_walk($input, function($entry) use (&$output) {
    $output[$entry['id']] = $entry;
}); 

array_walk($output, function (&$entry, $id) use (&$output) {
    $parent = $entry['parent'];
    unset($entry['parent']);
    // if entry belongs into a parent, then move it there
    if (array_key_exists($parent, $output)) {
        $output[$parent]['children'][] = $entry;
        unset($output[$id]);
    }
});

print_r($output);

The output is:

Array
(
    [4] => Array
        (
            [id] => 4
            [message] => D
        )

    [1] => Array
        (
            [id] => 1
            [message] => A
            [children] => Array
                (
                    [0] => Array
                        (
                            [id] => 2
                            [message] => B
                            [children] => Array
                                (
                                    [0] => Array
                                        (
                                            [id] => 3
                                            [message] => C
                                        )

                                )

                        )

                )

        )

)

answered Aug 9, 2019 at 17:43

arkascha

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5 Comments

arkascha Over a year ago

What a sphinx line comment... Would you care to elaborate why it is "not exactly working" and what you actual situation is? ;-)

Hamza Dhamiya Over a year ago

I didn't got the desired out, as you mentioned in the answer.

arkascha Over a year ago

You mean the code above gave another output in your case? Are you sure you didn't alter it?

Hamza Dhamiya Over a year ago

No I didn't alter it. Thanks anyways.

arkascha Over a year ago

Then I fail to understand what you mean by your last comment. The output created by that code is exactly the desired output, according to your question.

Hamza Dhamiya · Accepted Answer · 2019-08-10 20:05:49Z

0

This is the final code for someone's help

public static function commentRecursive($comments,$n){
        if(isset($comments[$n])){
            self::$str.="<ul>";
            foreach($comments[$n] as $comment){
                self::$str.=$comment['comment_content'];
                self::commentRecursive($comments,$comment['comment_id']);
            }
            self::$str.="</ul>";
        }
    }
    public static function commentsDataStructure($comments){
        self::$str='';
        $output=[];
        foreach ($comments as $comment){
            $output[$comment['comment_reply_to']][]=$comment;
        }
        self::commentRecursive($output,0);
        return self::$str;
    }

answered Aug 10, 2019 at 20:05

Hamza Dhamiya

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