How to convert object to json string array in php

In PHP programming, we often need to convert objects into json string arrays. This operation is very common in web development and can be used to pass data to the client or server, and also to share data between different applications. In this article we will explain how to convert an object into a json string array using php.

1. What is json?

JSON stands for JavaScript Object Notation, which is a lightweight data exchange format. JSON is based on JavaScript syntax, but does not depend on JavaScript, so it can be easily used in various programming languages. JSON uses key/value pairs to represent data, and its data structure is similar to a dictionary in Python. JSON represents data as an object (Object) or an array (Array). A JSON object is a collection of key/value pairs, where the key is a string and the value can be a string, number, Boolean value, array, object, etc. A JSON array is an ordered collection in which each element can be a value of any type (including objects and arrays).

Second, the json_encode function in php

The json_encode function in php is used to convert php variables into JSON format strings. Its syntax is as follows:

json_encode($value, $options = 0, $depth = 512)

$value: The variable to be converted to json format can be any data type, including Arrays, objects, Boolean types, integers, floating point numbers, null, etc.

$options: Optional parameters, used to determine the behavior of conversion. Common options include JSON_PRETTY_PRINT (formatted output), JSON_UNESCAPED_SLASHES (not escaping backslashes), etc. For a complete list, please refer to the official PHP documentation.

$depth: Optional parameter used to control the depth of conversion. Data beyond this depth will be converted to null. The default depth is 512.

The json_encode function converts the variable into a json format string that can be transmitted over the network or stored in a file.

Three, convert the object into a json string array

In PHP, converting the object into a json string array is very simple. We just need to convert the object into an associative array and then use the json_encode function to convert the array into a json string.

The following is a simple example that demonstrates how to convert an object in php to a json string array:

// Define a Person class
class Person
{

public $name;
public $age;
public $city;

public function __construct($name, $age, $city) 
{
    $this->name = $name;
    $this->age = $age;
    $this->city = $city;
}</p>
<p>}</p>
<p>// Instantiate the Person class<br>$person = new Person('Tom', 28, 'Shanghai');</p>
<p>// Convert object to associative array <br>$arr ​​= [</p>
<pre class="brush:php;toolbar:false">'name' => $person->name,
'age' => $person->age,
'city' => $person->city,

];

// Convert array to json string
$json = json_encode($arr );

//Print json string
echo $json;
?>

The output result of the above code is:

{"name": "Tom","age":28,"city":"Shanghai"}

In the above example, we first define a Person class and instantiate an object. We then convert the object to an associative array and use the json_encode function to convert the array to a json string. Finally, we printed the json string on the screen.

Four, convert nested objects into json string arrays

If you want to convert nested objects into json string arrays, you need to recursively traverse the entire object tree and convert each sub-object into Convert to associative array. Here is an example that demonstrates how to convert a nested object into a json string array:

// Define a Person class
class Person
{

public $name;
public $age;
public $city;

public function __construct($name, $age, $city) 
{
    $this->name = $name;
    $this->age = $age;
    $this->city = $city;
} </p>
<p>}</p>
<p>// Define an Order class<br>class Order<br>{</p>
<pre class="brush:php;toolbar:false">public $id;
public $customer;

public function __construct($id, $customer) 
{
    $this->id = $id;
    $this->customer = $customer;
}

}

// Instantiate the Person and Order classes
$person = new Person('Tom', 28, 'Shanghai');
$order = new Order(1001, $person);

// Convert nested objects to json string arrays
$arr ​​= [

'id' => $order->id,
'customer' => [
    'name' => $order->customer->name,
    'age' => $order->customer->age,
    'city' => $order->customer->city,
],

];

// Convert array to json string
$json = json_encode($arr);

/ / Print json string
echo $json;
?>

The output result of the above code is:

{"id":1001,"customer":{"name ":"Tom","age":28,"city":"Shanghai"}}

In the above example, we defined two classes, Person and Order, and instantiated an Order object . We then convert the nested object into an associative array and use the json_encode function to convert the array into a json string. Finally, we printed the json string on the screen.

Five, summary

Converting objects in php to json string array is a very practical skill, it can effectively pass data to the client or server, and in different Share data between applications. In php, we can use the json_encode function to convert an object into a json string array. If you want to convert a nested object into a json string array, you need to recursively traverse the entire object tree and convert each sub-object into an associative array. Hope this article is helpful to everyone.

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