First look at a JS function
Copy Code code as follows:
function Jsontest ()
{
var json = [{' username ': ' crystal ', ' userage ': '},{' username ': ' Candy ', ' userage ': ' 24 '}];
alert (json[1].username);
var json2 = [[' Crystal ', '],[' Candy ', ' 24 ']];
Alert (json2[0][0]);
}
This function, the first alert (json[1].username); Will prompt "Candy". A JSON variable is an array object. So you want to use a format such as Obj.username to invoke.
The second alert (json2[0][0]); Will prompt "Crystal". The Json2 variable is a full JSON format. Both JSON and JSON2 variables have the same effect, but json2 is significantly leaner than JSON.
This is the JSON format for JavaScript.
Now let's look at the JSON format in PHP.
Or look at a piece of code first.
Copy Code code as follows:
$arr = Array (
Array (
' CatID ' => ' 4 ',
' CatName ' => ' Chengcheng ',
' Meta_title ' => ' Chengcheng blog '
),
Array (
' CatID ' => ' 6 ',
' CatName ' => ' climber ',
' Meta_title ' => ' climber ',
)
);
$jsonstr = Json_encode ($arr);
Echo $jsonstr;
In this code, $arr is an array, and we use Json_encode to convert $arr to JSON format.
This piece of code will output:
[{"CatID": "4", "CatName": "\u7a0b\u7a0b", "Meta_title": "\u7a0b\u7a0b\u535a\u5ba2"},{"catid": "6", "CatName": " Climber "," Meta_title ":" \u6500\u767b\u8005 "}]
This is how PHP handles JSON data.
For JSON data, PHP can also use the Json_decode () function to convert JSON data to an array.
For example, in the above code, we use the Json_decode function to deal with. The above array is also printed out.
$jsonstr = Json_encode ($arr);
$jsonstr = Json_decode ($JSONSTR);
Print_r ($JSONSTR);
Next, let's look at how the PHP JSON data and the JS JSON data are invoked with each other.
We create a new php_json.php file
The code is as follows:
Copy Code code as follows:
$arr = Array (
Array (
' CatID ' => ' 4 ',
' CatName ' => ' Chengcheng ',
' Meta_title ' => ' Chengcheng blog '
),
Array (
' CatID ' => ' 6 ',
' CatName ' => ' climber ',
' Meta_title ' => ' climber ',
)
);
$jsonstr = Json_encode ($arr);
-----is written below the PHP range-----
var jsonstr=<? = $jsonstr? >;
PS: Var jsonstr=< at end of php_json.php file? = $jsonstr? >; This sentence. This is to assign the data in JSON format to the JSONSTR variable.
We'll build a json.html file.
The code is as follows:
Copy Code code as follows:
<script type=text/javascript src= "php_json.php" ></script><script language=javascript Javascript>
function Loadjson (_json)
{
if (_json)
{
for (Var i=0;i<_json.length;i++)
{
alert (_json[i].catname);
}
}
}
Loadjson (JSONSTR)
</SCRIPT>
In this way, when we look at the json.html, Loadjson (jsonstr) prompts "Chengcheng" and "climber".
This also implements the JS cross domain call.
