PHP json format and js json format js cross-domain call implementation code

PHP json format and js json format js cross-domain call implementation code_PHP tutorial

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Release： 2016-07-21 15:15:43

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First look at a js function

Copy code The code is as follows:

 
function jsontest() 
{ 
var json = [{'username':'crystal','userage':'20'},{'username':'candy','userage':'24'}]; 
alert(json[1].username ); 

var json2 = [['crystal','20'],['candy','24']]; 
alert(json2[0][0]); 
 } 

In this function, the first alert(json[1].username); will prompt "candy". The json variable is an array object. So it needs to be called in the format of obj.username.
The second alert(json2[0][0]); will prompt “crystal”. The json2 variable is a complete json format. Both json and json2 variables achieve the same effect, but json2 is obviously much more streamlined than json.
This is JavaScript’s json format.
Let’s take a look at the json format in php.
Let’s look at a piece of code first

Copy the code The code is 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, we use json_encode to change $ arr is converted to json format.
This code will output:

[{"catid":"4","catname":"u7a0bu7a0b","meta_title":"u7a0bu7a0bu535au5ba2"},{"catid":"6" ,"catname":"climber","meta_title":"u6500u767bu8005"}]
This is how PHP handles json data.
For json data, PHP can also use the json_decode() function to convert json data into an array.
For example, in the above code, we use the json_decode function to process it. The above array will be printed out again.
$jsonstr = json_encode($arr);
$jsonstr = json_decode($jsonstr);
print_r($jsonstr);
Next, let’s take a look at php json data and js json data How to call each other.

We create a new php_json.php file

The code is as follows:

Copy the code The code is 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); 
-----The following is written outside the php range----- 
var jsonstr=< ? = $jsonstr ? >; 

PS: At the end of the php_json.php file, var jsonstr=< ? = $jsonstr ? >; This sentence. This is to assign json format data to the jsonstr variable.
Let’s create another json.html file

The code is as follows:

Copy the code The code is as follows:

In this way, when we view json.html, loadjson(jsonstr) will Tip "Chengcheng" and "climber"
This also realizes js cross-domain calling.