PHP JSON

In this chapter, we will introduce how to use PHP to encode and decode JSON objects.

Environment Configuration

The JSON extension is built into PHP 5.2.0 and above.

JSON Functions

FunctionDescription
json_encode Encode a variable as JSON
json_decodeDecode a JSON string to a PHP variable
json_last_errorReturn the last error occurred

json_encode

PHP json_encode() is used to encode a variable as JSON. This function returns JSON data on success, or FALSE on failure.

Syntax

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

Parameters

  • value: The value to be encoded. This function only works with UTF-8 encoded data.

  • options: A bitmask composed of the following constants: JSON_HEX_QUOT, JSON_HEX_TAG, JSON_HEX_AMP, JSON_HEX_APOS, JSON_NUMERIC_CHECK, JSON_PRETTY_PRINT, JSON_UNESCAPED_SLASHES, JSON_FORCE_OBJECT, JSON_PRESERVE_ZERO_FRACTION, JSON_UNESCAPED_UNICODE, JSON_PARTIAL_OUTPUT_ON_ERROR.

    It should be noted that with the JSON_UNESCAPED_UNICODE option, if we don't want Chinese characters to be encoded, we can add this option.

Example

The following example demonstrates how to convert a PHP array to JSON format data:

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

The output of the above code is:

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

The following example demonstrates how to convert a PHP object to JSON format data:

Example

<?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', "8/5/1974 12:20:03 p");
   $e->birthdate = date('m/d/Y h:i:s a', strtotime("8/5/1974 12:20:03"));

   echo json_encode($e);
?>

The output of the above code is:

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

Using the JSON_UNESCAPED_UNICODE option

<?php
   $arr = array('example' => 'Rookie Tutorial', 'taobao' => 'Taobao');
   echo json_encode($arr); //Encode Chinese
   echo PHP_EOL;  //Newline character
   echo json_encode($arr, JSON_UNESCAPED_UNICODE);  //Do not encode Chinese
?>

The output of the above code is:

{"example":"\u83dc\u9e1f\u6559\u7a0b","taobao":"\u6dd8\u5b9d\u7f51"}
{"example":"Example","taobao":"淘宝网"}

json_decode

The PHP json_decode() function is used to decode a JSON string and convert it to a PHP variable.

Syntax

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

Parameters

  • json_string: The JSON string to be decoded. It must be UTF-8 encoded data.

  • assoc: When this parameter is TRUE, an array is returned; when FALSE, an object is returned.

  • depth: An integer parameter specifying the recursion depth.

  • options: A bitmask. Currently only JSON_BIGINT_AS_STRING is supported.

Example

The following example demonstrates how to decode JSON data:

Example

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

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

The output of the above code is:

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)
}
Other Extensions