Convert PHP to JSON with Nested Array

Question

I have a PHP variable I need to convert to JSON string.

I have following PHP code:

$username="admin";
$password="p4ssword";
$name="Administrator";
$email="[email protected]" 
$params=compact('username', 'password','name','email', 'groups');
json_encode($params);

This works fine. But what I am not sure about is how do I encode the properties in PHP with nested key value pairs shown below:

{
"username": "admin",
"password": "p4ssword",
"name": "Administrator",
"email": "[email protected]",
"properties": {
 "property": [
 {
 "@key": "console.rows_per_page",
 "@value": "user-summary=8"
 },
 {
 "@key": "console.order",
 "@value": "session-summary=1"
 }
 ]
 }
}

What is this with @ before key value?

• Phil: Are you asking how to create the JSON shown in your question as a PHP object / array?
• Matthew Herbst: Where are you getting that JSON output from? PHP's json_encode will encode any variable to JSON, regardless of how nested it is.
• user914425: @MatthewHerbst I am not sure how to specify the nested arrays (properties) in PHP to pass it into json_encode.

Answer 1

Something like this should do it

$username="admin"; //more variables
$params=compact('username' /* more variables to be compacted here*/);
$params["properties"] = [ 
 "property" => [
 [
 "@key" => "console.rows_per_page",
 "@value"=> "user-summary=8"
 ],
 [ 
 "@key"=> "console.order",
 "@value"=> "session-summary=1"
 ]
 ]
];
echo json_encode($params);

The manual has more examples you can use

Notice that:

• A key~value array is encoded into an object
• A regular array (array of arrays here) is encoded into an array

Those are all the rules you need to consider to encode any arbitrary object

Answer 2

Something like this perhaps?

$properties = [
 'property' => [
 ['@key' => 'console.rows_per_page', '@value' => 'user-summary=8'],
 ['@key' => 'console.order', '@value' => 'session-summary=1']
 ]
];

It's difficult to tell what you're asking.

• user914425: thank you! I will pass $properties to json_encode()

Answer 3

You can nest in PHP using simple arrays, very similar to JavaScript objects:

$grandparent = array(
 "person1" => array(
 "name" => "Jeff",
 "children" => array(
 array("name" => "Matt"),
 array("name" => "Bob")
 )
 ), 
 "person2" => array(
 "name" => "Dillan",
 "children" => array()
 )
);