Converting PHP Array to JSON

What is PHP?

PHP is an open-source server-side scripting language that can be embedded into HTML code. PHP supports multiple databases, including MySQL, PostgreSQL, and SQLite, and runs on various operating systems such as Linux, Windows, macOS, and Unix.

What is JSON?

JSON (JavaScript Object Notation) is a language-independent text format for storing and exchanging data. Developers use JSON in web server communications that require the exchange of structured data between a client and a server. Many programming languages have built-in or external libraries for creating and manipulating JSON data strings, including PHP, JavaScript, Java, C++, C#, Go, and Python. JSON file names use the .json extension.

What is an array in PHP?

In PHP, an array is a variable that is used to store data containing various elements. The elements of an array are identified by a unique key or index, which can be a number or a string. PHP has two types of arrays: indexed arrays and associative arrays. PHP provides many built-in functions for working with arrays, including searching, sorting, splitting a string to array, converting an array to string, getting the length of an array, and converting an array to JSON.

How to encode a PHP array into a JSON string?

To encode a PHP array into a JSON string, you can use json_encode() method to convert both array types to a JSON data string. The following is an example of converting an associative array to a JSON string:

<?php
$arr = array(
  'US' => 'Washington',  
  'UK' => 'London',
  'Spain' => 'Madrid', 
  'Italy' => 'Rome'
); 

echo json_encode($arr);
?>

#output: {"US":"Washington","UK":"London","Spain":"Madrid","Italy":"Rome"}

Converting PHP Array to JSON Examples

The following are examples of converting a PHP array to JSON:

Converting an array to a pretty JSON

The following is an example of converting an array to beautiful JSON using the json_encode() method:

<?php
$arr = array(
  'US' => 'Washington',  
  'UK' => 'London',
  'Spain' => 'Madrid', 
  'Italy' => 'Rome'
); 

echo json_encode($arr, JSON_PRETTY_PRINT);
?>

#output: 
# {
#   "US": "Washington",
#   "UK": "London",
#   "Spain": "Madrid",
#   "Italy": "Rome"
# }

Converting an array to JSON

The following is an example of converting an array to JSON using the json_encode() method:

<?php
$arr = array('PHP', 'Array', 'to', 'JSON');

echo json_encode($arr);
?>

#output: ["PHP","Array","to","JSON"]

Converting an associative array to JSON

The following is an example of converting an associative array to JSON using the json_encode() method:

<?php
$arr = array('name' => 'Leo', 'age' => 26, 'city' => 'London');

echo json_encode($arr);
?>

#output: {"name":"Leo","age":26,"city":"London"}

Converting a multidimensional associative array to JSON

The following is an example of converting a multidimensional associative array to JSON using the json_encode() function:

<?php
$arr = array (
  'first"' => array(
    'id'=> 1,
    'product' => 'Pineapple',
    'price' => 90
  ),
  'second' => array(
    'id' => 2,
    'product' => 'Orange',
    'price' => 70
  )
);

echo json_encode($arr);
?>

#output: {"first\"":{"id":1,"product":"Pineapple","price":90},"second":{"id":2,"product":"Orange","price":70}}

See also

• How do I POST JSON using PHP Curl Library?
• How to post form data in PHP?
• How do I convert JSON to PHP array?