How to use json_decode() and json_encode() in php?

json_decode encodes JSON-formatted strings, while json_encode JSON-encodes variables. The following article will introduce to you how to use json_decode() and json_encode(). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

1. json_encode() JSON encoding of variables

Syntax:

json_encode ( $value [, $options = 0 ] )

Note:

1. $value is the value to be encoded, and this function is only valid for UTF8 encoded data;

2. options: a binary mask composed of the following constants: JSON_HEX_QUOT, JSON_HEX_TAG, JSON_HEX_AMP, JSON_HEX_APOS, JSON_NUMERIC_CHECK, JSON_PRETTY_PRINT, JSON_UNESCAPED_SLASHES, JSON_FORCE_OBJECT;

3. The second parameter is generally not needed;

4. The json data is actually a string, and you can use var_dump() to print it out and view the data. Type;

5. JSON data is returned if the execution is successful, otherwise FALSE is returned.

eg:

//执行代码
$book = array('a'=>'lzichun','b'=>'nihao','c'=>'wohenhao','d'=>'ljlong');
$json = json_encode($book);
echo $json;

//打印出的结果
{"a":"lzichun","b":"nihao","c":"wohenhao","d":"ljlong"}

2. json_decode() decodes JSON data and converts it into PHP variables

Syntax:

json_decode (json[,json [,json[,assoc = false [, $depth = 512 [, $options =0 ]]])

Note:

1. $json is the data to be decoded, which must be utf8-encoded data;

2. $assoc returns an array when the value is TRUE, and an object when FALSE;

3, $ depth is the recursion depth;

4, $option binary mask, currently only supports JSON_BIGINT_AS_STRING;

5, generally only use the first two parameters, if you want data Type data needs to add a parameter true.

eg:

//执行代码
$book = array('a'=>'xiyouji','b'=>'sanguo','c'=>'shuihu','d'=>'hongloumeng');
        $json = json_encode($book);
        $array = json_decode($json,TRUE);
        $obj = json_decode($json);
        var_dump($array);
        var_dump($obj);
        
//打印出的结果
array(4) { ["a"]=> string(7) "xiyouji" ["b"]=> string(6) "sanguo" ["c"]=> string(6) "shuihu" ["d"]=> string(11) "hongloumeng" }
object(stdClass)#2 (4) { ["a"]=> string(7) "xiyouji" ["b"]=> string(6) "sanguo" ["c"]=> string(6) "shuihu" ["d"]=> string(11) "hongloumeng" }

The two results don’t look much different, but when calling the elements inside, the methods of array and obj are different.

//执行代码
$book = array('a'=>'xiyouji','b'=>'sanguo','c'=>'shuihu','d'=>'hongloumeng');
$json = json_encode($book);
$array = json_decode($json,TRUE);
$obj = json_decode($json);
var_dump($array['b']);//调用数组元素
echo &#39;<br/>&#39;;
var_dump($obj->c);//调用对象元素

//打印出的结果
string(6) "sanguo"
string(6) "shuihu"

This article is reproduced from: https://blog.csdn.net/longgeaisisi/article/details/84665523

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