PHP - Ds Map::jsonSerialize() Function

The PHP Ds\Map::jsonSerialize() function is used to retrieve a representation of elements that can be converted to JSON format.

The JSON stands for "JavaScript Object Notation" is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects consisting of attribute-value pairs and arrays.

Note: This function should never be called directly.

Syntax

Following is the syntax of the PHP Ds\Map::jsonSerialize() function −

public JsonSerializable::jsonSerialize(): mixed

Parameters

This function does not accept any parameter.

Return value

This function returns the representation that can be converted to JSON.

Example 1

The following is the basic example of the PHP Ds\Map::jsonSerialize() function −

<?php
class Demo implements JsonSerializable {
    public function __construct(array $my_arr) {
        $this->array = $my_arr;
    }

    public function jsonSerialize(){
        return $this->array;
    }
}
$my_arr = [10, 20, 30, 40, 50];
echo "The elements before converting to JSON format: \n";
print_r($my_arr);
echo "The elements after converting to JSON format: \n";
echo json_encode(new Demo($my_arr), JSON_PRETTY_PRINT);
?>

Output

The above program displays the following output −

The elements before converting to JSON format:
Array
(
    [0] => 10
    [1] => 20
    [2] => 30
    [3] => 40
    [4] => 50
)
The elements after converting to JSON format:
[
    10,
    20,
    30,
    40,
    50
]

Example 2

Following is another example of the PHP Ds\Map::jsonSerialize() function. We use this function to retrieve a representation that can be converted to JSON format −

<?php
class Demo implements JsonSerializable {
    public function __construct(array $vowels) {
        $this->array = $vowels;
    }
    public function jsonSerialize(){
        return $this->array;
    }
}
$vowels = ['a', 'e', 'o', 'i', 'u'];
echo "The elements before converting to JSON format: \n";
print_r($vowels);
echo "The elements after converting to JSON format: \n";
echo json_encode(new Demo($vowels), JSON_PRETTY_PRINT);
?>

Output

After executing the above program, the following output will be displayed:

The elements before converting to JSON format:
Array
(
    [0] => a
    [1] => e
    [2] => o
    [3] => i
    [4] => u
)
The elements after converting to JSON format:
[
    "a",
    "e",
    "o",
    "i",
    "u"
]