Adds a new object to a specific existing array name and saves it using the index value

Question

I know the best way is probably to save the new object at the end of the existing array without a name, but I want to make it a little more complicated to learn how to do this and have it at index value [0] of the array instead A new object is added at the end [arr.length - 1] and I need to save it in a specific array name because in this example I will have multiple arrays. Information is collected by HTML forms.

What I have is:

<?php
    
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
                
    function get_data() {
        $file_name='newsFeeder'. '.json';

        if(file_exists("./feeder/{$file_name}")) {
            $current_data=file_get_contents("./feeder/{$file_name}");
            $array_data=json_decode($current_data, true);

            $extra=array(
                'year' => $_POST['year'],
                'link' => $_POST['link'],
                'img' => $_POST['img'],
            );

            $array_data[]=$extra;
            echo "file exist<br/>";
            return json_encode($array_data, JSON_PRETTY_PRINT);
        }
        else {
            $datae=array();
            $datae[]=array(
                'year' => $_POST['year'],
                'link' => $_POST['link'],
                'img' => $_POST['img'],
            );
            echo "file not exist<br/>";
            return json_encode($datae, JSON_PRETTY_PRINT);
        }
    }

    $file_name='newsFeeder'. '.json';
    
    if(file_put_contents("./feeder/{$file_name}", get_data())) {
        echo 'success';
    }               
    else {
        echo 'There is some error';             
    }
}
    
?>

The result is a JSON file like this:

[
    {
        "year": "2022",
        "link": "xxxxxx_01.html",
        "img": "xxxxxx_01.webp"
    },
    {
        "year": "2023",
        "link": "xxxxxx_02.html",
        "img": "xxxxxx_02.webp"
    },
        .
        .
        .
        .
    {      // <- 这是在索引值[arr.length - 1]处添加的最新对象 //
        "year": "2024",
        "link": "xxxxxx_03.html"
    }
]

But what I want to achieve is this:

{
    "newsFeeder": [   // <- 这是我需要添加新对象的数组 //
        {      // <- 这是在索引值[0]处添加的最新对象 //
            "year": "2024",
            "link": "xxxxxx_06.html",
            "img": "xxxxxx_06.webp"
        },
        .
        .
        .
        .
        {
            "year": "2023",
            "link": "xxxxxx_02.html",
            "img": "xxxxxx_02.webp"
        },
        {
            "year": "2022",
            "link": "xxxxxx_01.html",
            "img": "xxxxxx_01.webp"
        }
    ],

    "whyComplicate_things":[      // 我需要保持此数组不变 //
        {"a":"01.webp", "title":"title 01"},
        {"a":"02.webp", "title":"title 02"},
        {"a":"03.webp", "title":"title 03"}
    ]
}

I've tried different methods, but those either clear everything and only add the collected information, or end up breaking things. Hope this helps me learn how to achieve this goal!

Answer 1

To add an element to the beginning of an array, if you are using PHP > 7.4, you can append using , ...$array_name.

Similar to the following code:

$array_name = [array(
    'year' => $_POST['year'],
    'link' => $_POST['link'],
    'img' => $_POST['img']
), ...$array_name];

Answer 2

You can use array_unshift to achieve this function. It shifts all array elements backward one and inserts the second parameter at index 0 of the first parameter of the function call.

array_unshift($array_data, $extra);