格式化json编码，就像在laravel php上一样

Question

Supposed I have a query that gets the image from a certain tweet

[
     {
         "pic": "/upload/15680712995mb.jpg",
        "tweet_id": "48"
     },
     {
         "pic": "/upload/1568071299test.PNG",
         "tweet_id": "48"
     },
     {
         "pic": "/upload/1568015310test.PNG",
         "tweet_id": "47"
     } 
]

And I have a result also from a query that gets all of the tweet

[
    {
        "id": "48",
        "tweet": "test",
    },
    {
        "id": "47",
        "tweet": "test tweet",
    },

    {
        "id": "45",
        "tweet": "test tweet 3",
    }
]

How can I format the result like this (Just like on laravel)

[
    {
        "id": "48",
        "tweet": "test",
        "pics": [
            [
                "/upload/15680712995mb.jpg"
            ],
            [
               "/upload/1568071299test.PNG"
            ],
        ]
    },
    {
        "id": "47",
        "tweet": "test tweet",
        "pics" : [
            [
                 "/upload/1568015310test.PNG"
            ]
        ]
    },
    {
        "id": "45",
        "tweet": "test tweet 3",
        "pics" : []
    }
]

And this is my simplified code

public function getTweets()
{
    $pics =  $this->model->getPics();

    $aTweets =  $this->model->getTweets();
    $map = [];
    $props = [];
    foreach ($aTweets as $sTweet) {
        $map['id'] =  $sTweet['id'];
        $map['tweet'] =  $sTweet['tweet'];

        foreach ($pics as $pic) {
            if ($pic['id'] === $sTweet['tweet_id']) {
                $map['pics'] = [$pic['pic']];
            }
        }

        $props[] = $map;

    }
    return $props;
}

but it just gives me the following output

{
    "id": "48",
    "tweet": "test",
    "pics": [
        "/upload/1568015310test.PNG"
    ]
},
{
    "id": "47",
    "tweet": "test tweet",
    "pics": [
        "/upload/1568015310test.PNG"
    ]
},

Any idea how can I format the result. thanks in advance.?

Answer 1

I'm not sure what's troubling you but in order to add multiple values inside, just put another nesting like what I've eluded in the comments section:

$map['pics'][] = $pic['pic'];
        //   ^

So to complete the answer:

$map = [];
$props = [];
foreach ($aTweets as $sTweet) {
    $map['id'] =  $sTweet['id'];
    $map['tweet'] =  $sTweet['tweet'];
    $map['pics'] = []; // initialize
    foreach ($pics as $pic) {
        if ($pic['tweet_id'] === $sTweet['id']) {
            $map['pics'][] = [$pic['pic']];
        }
    }

    $props[] = $map;
}

This essentially creates another dimension for pics index as an array and continually pushing, provided they have the same ID.

Sidenote: tweet_id is to pics and id is to aTweets . Your's have the other way around.