Use JSON in PHP

Use JSON in PHP

This tutorial will teach us how to encode and decode JSON objects using the PHP programming language. Let's prepare the environment for PHP programming for JSON.

Environment

The JSON extension is bundled by default and compiled into PHP starting with PHP 5.2.0.

JSON function

Using PHP to encode JSON (json_encode)

PhP's json_encode() function is used to encode JSON in PHP. When encoding is successful, the function returns the JSON representation of a given value, and if it fails, false.

Grammar:

string json_encode ( $value [, $options = 0 ] )

Parameters:

• Value: The value to encode. This function can only be used for UTF-8 encoded data.
• Options: This optional value is a bit mask consisting of JSON_HEX_QUOT, JSON_HEX_TAG, JSON_HEX_AMP, JSON_HEX_APOS, JSON_NUMERIC_CHECK, JSON_PRETTY_PRINT, JSON_UNESCAPED_SLASHES, JSON_FORCE_OBJECT, and so on.

Example:

The following example shows how to convert an array to JSON using PHP:

<?php
    $arr = array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5);
    echo json_encode($arr);
?>

The execution produces the following results:

{"a":1,"b":2,"c":3,"d":4,"e":5}

The following example shows that PHP objects can also be converted to JSON:

<?php
    class Emp {
        public $name = "";
        public $hobbies  = "";
        public $birthdate = "";
    }
    $e = new Emp();
    $e->name = "sachin";
    $e->hobbies  = "sports";
    $e->birthdate = date('m/d/Y h:i:s a', strtotime("8/5/1974 12:20:03"));

    echo json_encode($e);
?>

The execution produces results such as the following:

{"name":"sachin","hobbies":"sports","birthdate":"08\/05\/1974 12:20:03 pm"}

Decode JSON (json_decode) json_decode PHP

The json-decode() function of PHP is used to decode JSON in PHP. This function returns a value from JSON decoding to the appropriate PHP type.

Grammar:

mixed json_decode ($json [,$assoc = false [, $depth = 512 [, $options = 0 ]]])

Parameters:

• __json_string: , the encoded string must be UTF-8 encoded data.
• Assoc: It is a Boolean-type argument, and when set to TRUE, the returned object is converted to an associated array.
• Depth: It is an integer parameter that specifies the recursive depth.
• Options: It is an integer bit mask decoded by JSON. Support JSON_BIGINT_AS_STRING.

Example:

The following example shows how to decode a JSON object using PHP:

<?php
    $json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';

    var_dump(json_decode($json));
    var_dump(json_decode($json, true));
?>

The results are generated on execution as follows:

object(stdClass)#1 (5) {
    ["a"] => int(1)
    ["b"] => int(2)
    ["c"] => int(3)
    ["d"] => int(4)
    ["e"] => int(5)
}

array(5) {
    ["a"] => int(1)
    ["b"] => int(2)
    ["c"] => int(3)
    ["d"] => int(4)
    ["e"] => int(5)
}