PHP operation json

json only accepts utf-8 encoded characters, so the parameters of php’s function json_encode() must be utf-8 encoded

json format:

============ ================

Wrong json format:

$error_json = "{ 'name': 'jack' }"; //json delimiter Only double quotes are allowed, single quotes are not allowed
$error_json = '{ name: "jack" }'; //The "key" (the part to the left of the colon) of the json key-value pair must use double quotes
$error_json = ' { "name": "baz", }'; //Comma cannot be added after the last value

========================== ====

Correct json format

$yes_json= '{"name":"jack"}';

Operation under PHP:

(1).json_encode( )Function: Convert arrays and objects to json format

For example:

①Convert array of key/value pairs to json format, which will become json in object form

　$arr = array ( 'a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);
　echo "After jsonization, arr is: ".json_encode($arr);
　============================================ =========
　 After jsonization, arr is: {"a":1,"b":2,"c":3,"d":4,"e":5}

②Convert the index array to json format, which will become json in array form　

　 $arr = Array('one', 'two', 'three');
　echo json_encode($arr);
　== ================================================
　　[ "one","two","three"]

Force the index array into an object:

　json_encode( (object)$arr );
　Or
　json_encode ( $arr, JSON_FORCE_OBJECT );

③Convert the class object to json format, retaining only the public fields

class ClassA {　
　　 const ERROR_CODE = '404';
　　public $public_var = 'this is public_var';　
　　private $ private_var = 'this is private_var';
　　protected $protected_var = 'this is protected_var'; ===============================



$ClassA = new ClassA; $classA_json = json_encode($ClassA) ;　

echo $classA_json;

=========================================={" public_var":"this is public_var"}

(2).json_decode() function, converts the string in json format into a php variable. By default, it is converted into an object object. When the second parameter is passed in When it is true, it will be converted into a php array

For example:

①. Converted into a php object

$json = '{"a":1,"b":2,"c":3 ,"d":4,"e":5}var_dump($json);

============================== ================

object(stdClass)#1 (5) { ["a"] => int(1) ["b"] => int (2)

["c"] => int(3)

["d"] => int(4) ["e"] => int(5)
}



②. Convert to php array



$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}'; var_dump(json_decode( $json, true));

============================================ ===

array(5) { ["a"] => int(1) ["b"] => int(2)

["c"] => int(3)

[ "d"] => int(4) ["e"] => int(5)
}


The above introduces the PHP operation json, including the content. I hope it will be helpful to friends who are interested in PHP tutorials.