使用PHP创建带有数组的JSON对象[关闭]

How can I create following type JSON object using PHP? I want this JSON for my Android app.

    {
  "grade 3": [
    {
      "section": "A",
      "img_url": "http://lyceumssports.com/Chrysanthemum.jpg"
    },
    {
      "section": "B",
      "img_url": "http://lyceumssports.com/Penguins.jpg"
    },
    {
      "section": "C",
      "img_url": "http://lyceumssports.com/Penguins.jpg"
    }
  ],
  "grade 2": [
    {
      "section": "A",
      "img_url": "http://lyceumssports.com/Chrysanthemum.jpg"
    },
    {
      "section": "B",
      "img_url": "http://lyceumssports.com/Penguins.jpg"
    },
    {
      "section": "C",
      "img_url": "http://lyceumssports.com/Penguins.jpg"
    }
  ],
  "grade 1": [
    {
      "section": "CD 1",
      "img_url": "http://lyceumssports.com/Chrysanthemum.jpg"
    },
    {
      "section": "CD 2",
      "img_url": "http://lyceumssports.com/Penguins.jpg"
    }
  ]
}

Here I want JSON object having arrays with keys an that array also has JSON Objects.

Use a php function called json_encode($array). Pass the array into the function and it will give you the json object.
If you want to print JSON object beautifully then add an extra argument JSON_PRETTY_PRINT, like json_encode($json, JSON_PRETTY_PRINT);. Store this object into a variable and use that variable. On the other side you need to decode the JSON object, like in php,

$json_object=json_encode($json, JSON_PRETTY_PRINT);
$json_decode=json_decode($json_object);

For more details see this link, JSON.