everest ultimate edition PHP6 preparatory course JSON example code

It is a subset based on JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999
JSON mainly uses pairs of {} to wrap each object (object), and pairs of [] to wrap each array( array),
Use pairs of "" to wrap each string, use commas to separate each variable, and the data types include string, number, array, object
The following simple JSON format describes an object json that has an Member variable, this member variable contains three objects
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var json = {
'query' : [
{'id':'1','type':'a',' title':'PHP 5.2.0's new function JSON decoder & encoder'},
{'id':'2','type':'b','title':'JSON full name JavaScript Object Notation'},
{'array': ['A', 'B','C', 'D', 'E']}
]
};
In this way, we can get an Object called json, and this json Object contains An independent member query
And query contains an Array. This Array contains three Objects. The first two Objects contain three members
id, type, title, and the last Object array contains an array. This explanation is also clear. Bar?
But how to use it?
Very simple
alert('I have ' +json.query.length + ' object.');
//alert I have 3 object.
alert('type='+json.query[1].type+'rntitle '+json.query[1].title);
//alert type=b title=JSON full name JavaScript Object Notation
alert('array index 3='+json.query[2].array[3]);
//alert array index 3=D
This makes it easier to operate data. There is no need to deal with complex DOM. The required data can be easily obtained
For example, the above example json.query[ i ].title can be obtained in this way The value contained in the i-th title
PHP is developing very rapidly. When the programming world still has little knowledge of JSON or has no idea what JSON is at all
PHP has been incorporated into the core in the latest version 5.2.0, and the default state Yes, compared to other Script languages ​​
PHP is leading the way. In version 5.2.0, it has implemented two functions json_decode() and json_encode() for JSON
The former restores JSON format strings to PHP native Array
The latter compiles PHP native array into a string in JSON format
However, since Javascript supports Unicode, if you use non-Ascii characters when accessing the database, such as Chinese, Japanese, and Korean
You need to change the characters Convert the encoding to UTF8, otherwise the string after json_encode() will be garbled
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After a brief introduction to JOSN in the previous article
This article will implement how to use JOSN
The following examples require the use of MySQL4 . Version 1 or above
The whole coding process uses utf8
Follow the data format of the previous article. There are three fields in the table: id, type, title
The specifications of the data table are as follows
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CREATE TABLE `news` (
` id` int(10) unsigned NOT NULL auto_increment,
`type` varchar(255) NOT NULL default '',
`title` varchar(64) NOT NULL default '',
PRIMARY KEY (`id`)
) ENGINE =MyISAM AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;
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//Establish connection
$conn = mysqli_connect("localhost", 'root', '')or die( 'Unable to connect to the database');
//Select the database
mysqli_select_db($conn,'mydata') or die('Can't select the database');
//Set the connection encoding rules, don't know how to use google Find
mysqli_query($conn,'SET NAMES 'utf8'');
//Get data
$results = mysqli_query($conn,'SELECT id,type,title FROM news');
//Josn string
$ json = '';
//Because it is an example, you can control the loop by yourself
$i=0;
while($row = mysqli_fetch_assoc($results))
{
$i++;
$json .= json_encode($row );
//There are only three pieces of data in the data table, so there is no need to add "," at the end of the third piece of data. Remember, there is no need to add "," to the last piece of data
if ($i<3)
{
$json .= ",";
}
}
//Pack the data into the array
$json = '{"query":[ '.$json.']}';?>
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