php operation JSON format data implementation code

Knowledge:
1. Introduction to JSON data format
2. Encode the data into JSON format
3. Decode and operate JSON data
The data format of JSON is represented as follows:

 
{ "programmers": [ 
　　{ "firstName": "Brett", "lastName":"McLaughlin", "email": "aaaa" }, 
　　{ "firstName": "Jason", "lastName":"Hunter", "email": "bbbb" }, 
　　{ "firstName": "Elliotte", "lastName":"Harold", "email": "cccc" } 
　　], 
　　"authors": [ 
　　{ "firstName": "Isaac", "lastName": "Asimov", "genre": "science fiction" }, 
　　{ "firstName": "Tad", "lastName": "Williams", "genre": "fantasy" }, 
　　{ "firstName": "Frank", "lastName": "Peretti", "genre": "christian fiction" } 
　　], 
　　"musicians": [ 
　　{ "firstName": "Eric", "lastName": "Clapton", "instrument": "guitar" }, 
　　{ "firstName": "Sergei", "lastName": "Rachmaninoff", "instrument": "piano" } 
　　] } 

Encoding data into JSON format with php:

 
<?php 
//php I'm going to represent it as an array JSON Format data  
$arr = array( 
'firstname' => iconv('gb2312', 'utf-8', ' If you are the '), 
'lastname' => iconv('gb2312', 'utf-8', ' You are the one '), 
'contact' => array( 
'email' =>'fcwr@ofstack.com', 
'website' =>'//www.ofstack.com', 
) 
); 
// The array is encoded as JSON The data format  
$json_string = json_encode($arr); 
//JSON Format data can be output directly  
echo $json_string; 
?> 

It should be pointed out that Chinese characters cannot be encode under non-UTF-8 encoding, and the result will be null. Therefore, if you use gb2312 to write PHP code, then you need to use iconv or mb to UTF-8 to json_encode.
Output :(JSON format)
{"firstname":"\u975e\u8bda","lastname":"\u52ff\u6270","contact":{"email":"fcwr@ofstack.com","website":"http:\/\/www.ofstack.com"}}
Decode and process JSON data with php:

 
<?php 
//php I'm going to represent it as an array JSON Format data  
$arr = array( 
'firstname' => iconv('gb2312', 'utf-8', ' If you are the '), 
'lastname' => iconv('gb2312', 'utf-8', ' You are the one '), 
'contact' => array( 
'email' =>'fcwr@ofstack.com', 
'website' =>'//www.ofstack.com', 
) 
); 
// The array is encoded as JSON The data format  
$json_string = json_encode($arr); 
// will JSON Format data is decoded, decoded is not JSON Data format, not available echo Direct output  
$obj = json_decode($json_string); 
// Force conversion to array format  
$arr = (array) $obj; 
// The data inside is called as an array  
echo iconv('utf-8','gb2312',$arr['firstname']); 
echo '</br>'; 
// Output array structure  
print_r($arr); 
?> 

Output:
If you are the
Array ( [firstname] = > � � � [lastname] = > Hang hang [contact] = > stdClass Object ( [email] = > fcwr@ofstack.com [website] = > //www.ofstack.com ) )