PHP Beginner's Introduction to JSON

1. Environment configuration

In php5.2.0 and above versions, JSON extension has been built-in

2. JOSN () function

json_encode Perform the variable json encoding

# JSON_DECODE to decod in json format, convert it to PHP variables

json_last_error Return to return The last error that occurred

json_encode

is used to JSON encode the variable. If the function is successfully executed, it returns JSON data, otherwise it returns FALSE

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

Parameters:

value: The value to be encoded. This function is only valid for UTF-8 encoded data.

options: Binary mask consisting 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

## Example 1:How to convert a PHP array into json data

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

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

<?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);
?>

json_decode

PHP json_decode() function is used to decode JSON format strings and convert them into PHP variables.

Syntax

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

Parameters

json_string: JSON string to be decoded, must be UTF-8 encoded data

assoc: When this parameter is TRUE, an array will be returned, and when FALSE, an object will be returned.

depth: Integer type parameter, which specifies the recursion depth

options: Binary mask, currently only JSON_BIGINT_AS_STRING is supported.

Example

The following example demonstrates how to decode JSON data:

<?php
   $json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
   echo "<pre>";
   var_dump(json_decode($json));
   var_dump(json_decode($json, true));
   echo "</pre>";
?>