Add JSON Element To Multidimensional JSON Object PHP

Question

I have a JSON object in a file called info.json that looks like this -->

[
    {
        "name": "level0",
        "items": 
            [
                {
                    "name": "item1",
                    "type": "type1"
                },
                {
                    "name": "item2",
                    "type": "type2"
                }

            ]
    },
    {
        "name": "Level1",
        "items":
            [
                {
                    "name": "item4",
                    "type": "type4"
                },
                {
                    "name": "item5",
                    "type": "type5"
                }
            ]
    },
    {
        "name": "Level2",
        "items":
            [
                {
                    "name": "item6",
                    "type": "type6"
                }

            ]
    }
]

and a php script that looks like this -->

<?php

    $json_string = file_get_contents("info.json");
    $json = json_decode($json_string, true);

    array_push($json[0]["items"], array("name" => "item3", "type" => "type3"));
?>

I'm trying to insert a third element in the first instance of "items" in this array, such that when I open the JSON file the new element will appear. What am I doing wrong? Any advice would be appreciated, thanks.

the file itself is not changing, though the value of $json is. — laroy, Jun 19 '17 at 03:31
Your code is working fine. Do a `var_dump` on `$json` and see the result. — Imesha Sudasingha, Jun 19 '17 at 03:34
@KrisRoofe I'm looking to update the text in the file that the JSON object is stored, not just the value of the array when the program is run. — laroy, Jun 19 '17 at 03:35
@laroy is not [Sahan Serasinghe's answer](https://stackoverflow.com/a/44621883/6521116) you are expecting for? — LF00, Jun 19 '17 at 03:41
@KrisRoofe, no. The more I look into it, I think I need to use fwrite or something to change the actual file. — laroy, Jun 19 '17 at 03:43
@laroy then you just save it to your file with json_encode and file_put_contents. — LF00, Jun 19 '17 at 03:51

score 1 · Answer 1 · answered Jun 19 '17 at 03:31

1

Your code looks fine to me. Output the $json variable and you will be able to see your desired result.

print(json_encode($json, JSON_PRETTY_PRINT));

I made a sample for you: https://eval.in/818486

Hope this helps :)

answered Jun 19 '17 at 03:31

Sahan Serasinghe

1,591
20
33

score 1 · Accepted Answer · answered Jun 19 '17 at 04:24

1

After you have changed the $json array, you need to save it to your info.json file with this,

file_put_contents("info.json", json_encode($json));

answered Jun 19 '17 at 04:24

LF00

27,015
29
156
295

score 0 · Answer 3 · answered Jun 19 '17 at 04:51

Hello laroy you have not right the new json encode string to the file so your code will look like this

<?php

$json_string = file_get_contents("info.json");
$json = json_decode($json_string, true);
array_push($json[0]["items"], array("name" => "item3", "type" => "type3"));
$strNew = json_encode($json);
file_put_contents("info.json", $strNew);

?>

Now you can check the the info.json file.

Add JSON Element To Multidimensional JSON Object PHP

3 Answers3