json_decode详解

json_decode详解

  • 1.json_decode()

1.json_decode()

json_decode
(PHP 5 >= 5.2.0, PECL json >= 1.2.0)

json_decode — 对 JSON 格式的字符串进行编码

说明
mixed json_decode ( string $json [, bool $assoc ] )
接受一个 JSON 格式的字符串并且把它转换为 PHP 变量

参数

json
待解码的 json string 格式的字符串。

assoc
当该参数为 TRUE 时,将返回 array 而非 object 。

返回值
Returns an object or if the optional assoc parameter is TRUE, an associative array is instead returned.

范例

Example #1 json_decode() 的例子

代码如下
1
$json = ‘{“a”:1,“b”:2,“c”:3,“d”:4,“e”:5}’;

        var_dump(json_decode($json)); 

        var_dump(json_decode($json, true)); 

        ?>

2 上例将输出:
3 object(stdClass)#1 (5) {

        ["a"] => int(1) 

        ["b"] => int(2) 

        ["c"] => int(3) 

        ["d"] => int(4) 

        ["e"] => int(5) 

        }

4 array(5) {

        ["a"] => int(1) 

        ["b"] => int(2) 

        ["c"] => int(3) 

        ["d"] => int(4) 

        ["e"] => int(5) 

        }

5

        $data='[{"Name":"a1","Number":"123","Contno":"000","QQNo":""},{"Name":"a1","Number":"123","Contno":"000","QQNo":""},{"Name":"a1","Number":"123","Contno":"000","QQNo":""}]'; 

        echo json_decode($data);

6 结果为:
7 Array ( [0] => stdClass Object ( [Name] => a1 [Number] => 123 [Contno] => 000 [QQNo] => ) [1] => stdClass Object ( [Name] => a1 [Number] => 123 [Contno] => 000 [QQNo] => ) [2] => stdClass Object ( [Name] => a1 [Number] => 123 [Contno] => 000 [QQNo] => ) )
可以看出经过json_decode()编译出来的是对象,现在输出json_decode($data,true)试下

代码如下
1 echo json_decode( d a t a , t r u e ) ; 2 结 果 : 3 A r r a y ( [ 0 ] = > A r r a y ( [ N a m e ] = > a 1 [ N u m b e r ] = > 123 [ C o n t n o ] = > 000 [ Q Q N o ] = > ) [ 1 ] = > A r r a y ( [ N a m e ] = > a 1 [ N u m b e r ] = > 123 [ C o n t n o ] = > 000 [ Q Q N o ] = > ) [ 2 ] = > A r r a y ( [ N a m e ] = > a 1 [ N u m b e r ] = > 123 [ C o n t n o ] = > 000 [ Q Q N o ] = > ) ) 可 以 看 出 j s o n d e c o d e ( data,true); 2 结果: 3 Array ( [0] => Array ( [Name] => a1 [Number] => 123 [Contno] => 000 [QQNo] => ) [1] => Array ( [Name] => a1 [Number] => 123 [Contno] => 000 [QQNo] => ) [2] => Array ( [Name] => a1 [Number] => 123 [Contno] => 000 [QQNo] => ) ) 可以看出 json_decode( data,true);23Array([0]=>Array([Name]=>a1[Number]=>123[Contno]=>000[QQNo]=>)[1]=>Array([Name]=>a1[Number]=>123[Contno]=>000[QQNo]=>)[2]=>Array([Name]=>a1[Number]=>123[Contno]=>000[QQNo]=>))jsondecode(data,true)输出的一个关联数组,由此可知json_decode( d a t a ) 输 出 的 是 对 象 , 而 j s o n d e c o d e ( " data)输出的是对象,而json_decode(" data,jsondecode("arr",true)是把它强制生成PHP关联数组.

假如我们获取的JSON数据如下:(可以使用curl、fsockopen等方式获取)

代码如下
1 {

         "from":"zh",

         "to":"en",

         "trans_result":[

          {

           "src":"u4f60u597d",

           "dst":"Hello"

          }

         ]

        }

一、json_decode返回array的方式:

json_decode($data,true);用json_decode函数返回array的方式得到:

代码如下
1 Array

        (

            [from] => zh

            [to] => en

            [trans_result] => Array

                (

                    [0] => Array

                        (

                            [src] => 你好

                            [dst] => Hello

                        )

2 )
3 )
我们在PHP语言中可以用以下方法取得我们想要的值:

代码如下
1
$data = <<
{

         "from":"zh",

         "to":"en",

         "trans_result":[

          {

           "src":"u4f60u597d",

           "dst":"Hello"

          }

         ]

        }

        STR;

        $jsondata=json_decode($data,true);

        header("Content-Type: text/html; charset=UTF-8");

        print_r($jsondata);www.111com.net

        echo "

".$jsondata[‘to’]; //en

        echo "

".$jsondata[‘trans_result’][0][‘dst’]; //Hello

        ?>

二、json_decode返回object的方式:

json_decode($data);

用json_decode函数返回object的方式得到:

代码如下
1 stdClass Object

        (

            [from] => zh

            [to] => en

            [trans_result] => Array

                (

                    [0] => stdClass Object

                        (

                            [src] => 你好

                            [dst] => Hello

                        )

2 )
3 )
我们在PHP语言中可以用以下方法取得我们想要的值:

代码如下
1
$data = <<
{

         "from":"zh",

         "to":"en",

         "trans_result":[

          {

           "src":"u4f60u597d",

           "dst":"Hello"

          }

         ]

        }

2 STR;

        $jsondata=json_decode($data);

        header("Content-Type: text/html; charset=UTF-8");

        print_r($jsondata);

        echo "

".$jsondata->from; //zh

        echo "

".$jsondata->trans_result[0]->src; //你好

        ?>

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