Question

我从PHP输出一些JSON，但我很难理解如何进行嵌套数组（至少我认为这就是它的名称）

我可以输出单个集合，例如"type": "Feature"，但我该怎么做

"geometry": {
    "type": "Point",
    "coordinates": [-77.03238901390978,38.913188059745586]
},

例如，JSON数组中一个项目的所需输出可能是：

{
    "type": "Feature",
    "geometry": {
        "type": "Point",
        "coordinates": [-77.03238901390978,38.913188059745586]
    },
    "properties": {
        "title": "Mapbox DC",
        "description": "1714 14th St NW, Washington DC",
        "marker-color": "#fc4353",
        "marker-size": "large",
        "marker-symbol": "monument"
    }
},

到目前为止我的代码看起来像这样：

<?php 
$projects = $pages->find('template=project-detail, sort=sort');
$projects_array = array();

foreach ($projects as $project) {

    $title = $project->title;
    $long = $project->project_location_marker_long;
    $lat = $project->project_location_marker_lat;

    $projects_array[] = array(
        'title' => $title
    );

}

$projects_json = json_encode($projects_array, true);
?>
<script>
var geojson = <?php echo echo $projects_json; ?>
</script>

生成如下内容：

[{
    "title": "Steel Strike 1980"
}, {
    "title": "Chapel Flat Dyke Boat"
}]

Answer 1

嵌套数组很容易创建。这是一个例子：

$my_array = array(
    'string_example' => 'asdf',
    'integer_example' => 42,
    'array_example' => array() // this array is nested
);

在这个嵌套数组中，你可以放任何你想要的东西。例如，让我们把完全相同的东西放在其中：

$my_array = array(
    'string_example' => 'asdf',
    'integer_example' => 42,
    'array_example' => array(
        'string_example' => 'asdf',
        'integer_example' => 42,
        'array_example' => array()
    )
);

从代码示例开始，根据您包含的数据，这是一个开始：

foreach ($projects as $project) {

    $title = $project->title;
    $long = $project->project_location_marker_long;
    $lat = $project->project_location_marker_lat;

    $projects_array[] = array(
        'geometry' => array(
            'coordinates' => array($long, $lat)
        )
        'properties' => array(
            'title' => $title
        )
    );

}

这将在编码时产生以下json：

{
    "geometry": {
        "coordinates": [-77.03238901390978,38.913188059745586]
    },
    "properties": {
        "title": "Mapbox DC",
    }
}

Answer 2

有一种简单的方法可以解决这个问题。只需使用您的示例JSON，对其进行解码并查看输出结果：

<?php
$json = '
{
    "type": "Feature",
    "geometry": {
        "type": "Point",
        "coordinates": [-77.03238901390978,38.913188059745586]
    },
    "properties": {
        "title": "Mapbox DC",
        "description": "1714 14th St NW, Washington DC",
        "marker-color": "#fc4353",
        "marker-size": "large",
        "marker-symbol": "monument"
    }
}';
var_export(json_decode($json, true));

输出：

array (
  'type' => 'Feature',
  'geometry' => 
  array (
    'type' => 'Point',
    'coordinates' => 
    array (
      0 => -77.032389013909778,
      1 => 38.913188059745586,
    ),
  ),
  'properties' => 
  array (
    'title' => 'Mapbox DC',
    'description' => '1714 14th St NW, Washington DC',
    'marker-color' => '#fc4353',
    'marker-size' => 'large',
    'marker-symbol' => 'monument',
  ),
)

Answer 3

如果您想编码示例代码的lat / lon，那么它将是：

$title = $project->title;
$long = $project->project_location_marker_long;
$lat = $project->project_location_marker_lat;

$projects_array[] = array(
    'title' => $title,
    'coordinates' => array($lat,$lon)
);

这将导致类似这样的事情：

[{
    "title": "Steel Strike 1980",
    "coordinates": [-77.03238901390978,38.913188059745586]
}, {
    "title": "Chapel Flat Dyke Boat",
    "coordinates": [-77.03238901390978,38.913188059745586]
}]

来自PHP的JSON - 嵌套数组

3 个答案: