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

上例将输出：

object(stdClass)#1 (5) {
    ["a"] => int(1)["b"] => int(2)["c"] => int(3)["d"] => int(4)["e"] => int(5)}array(5) {["a"] => int(1)["b"] => int(2)["c"] => int(3)["d"] => int(4)["e"] => int(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);

结果为：

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

echo json_decode($data,true);

结果：

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($data,true)输出的一个关联数组,由此可知json_decode($data）输出的是对象,而json_decode("$arr",true)是把它强制生成PHP关联数组.

2.json_encode()

json_encode

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

json_encode — 对变量进行 JSON 编码

Report a bug 说明

string json_encode ( mixed $value [, int $options = 0 ] )

返回 value 值的 JSON 形式

Report a bug 参数

value

待编码的 value ，除了resource 类型之外，可以为任何数据类型

该函数只能接受 UTF-8 编码的数据

options

由 以下常量组成的二进制掩码： JSON_HEX_QUOT, JSON_HEX_TAG, JSON_HEX_AMP, JSON_HEX_APOS, JSON_NUMERIC_CHECK, JSON_PRETTY_PRINT, JSON_UNESCAPED_SLASHES, JSON_FORCE_OBJECT, JSON_UNESCAPED_UNICODE.

Report a bug 返回值

编码成功则返回一个以 JSON 形式表示的 string 或者在失败时返回 FALSE 。

Report a bug 更新日志

版本 说明

5.4.0 options 参数增加常量： JSON_PRETTY_PRINT, JSON_UNESCAPED_SLASHES, 和 JSON_UNESCAPED_UNICODE。

5.3.3 options 参数增加常量：JSON_NUMERIC_CHECK。

5.3.0 增加 options 参数.

Report a bug 范例

Example #1 A json_encode() 的例子

     1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);echo json_encode($arr);?>

以上例程会输出：

{"a":1,"b":2,"c":3,"d":4,"e":5}

Example #2 json_encode() 函数中 options 参数的用法

     ',"'bar'",'"baz"','&blong&', "\xc3\xa9");echo "Normal: ", json_encode($a), "\n";echo "Tags: ", json_encode($a, JSON_HEX_TAG), "\n";echo "Apos: ", json_encode($a, JSON_HEX_APOS), "\n";echo "Quot: ", json_encode($a, JSON_HEX_QUOT), "\n";echo "Amp: ", json_encode($a, JSON_HEX_AMP), "\n";echo "Unicode: ", json_encode($a, JSON_UNESCAPED_UNICODE), "\n";echo "All: ", json_encode($a, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE), "\n\n";$b = array();echo "Empty array output as array: ", json_encode($b), "\n";echo "Empty array output as object: ", json_encode($b, JSON_FORCE_OBJECT), "\n\n";$c = array(array(1,2,3));echo "Non-associative array output as array: ", json_encode($c), "\n";echo "Non-associative array output as object: ", json_encode($c, JSON_FORCE_OBJECT), "\n\n";$d = array('foo' => 'bar', 'baz' => 'long');echo "Associative array always output as object: ", json_encode($d), "\n";echo "Associative array always output as object: ", json_encode($d, JSON_FORCE_OBJECT), "\n\n";?>

以上例程会输出：

Normal: ["
     
      ","'bar'","\"baz\"","&blong&","\u00e9"]Tags: ["\u003Cfoo\u003E","'bar'","\"baz\"","&blong&","\u00e9"]Apos: ["
      
       ","\u0027bar\u0027","\"baz\"","&blong&","\u00e9"]Quot: ["
       
        ","'bar'","\u0022baz\u0022","&blong&","\u00e9"]Amp: ["
        
         ","'bar'","\"baz\"","\u0026blong\u0026","\u00e9"]Unicode: ["
         
          ","'bar'","\"baz\"","&blong&","é"]All: ["\u003Cfoo\u003E","\u0027bar\u0027","\u0022baz\u0022","\u0026blong\u0026","é"]Empty array output as array: []Empty array output as object: {}Non-associative array output as array: [[1,2,3]]Non-associative array output as object: {"0":{"0":1,"1":2,"2":3}}Associative array always output as object: {"foo":"bar","baz":"long"}Associative array always output as object: {"foo":"bar","baz":"long"}
         
        
       
      
     

Example #3 连续与非连续数组示例

     "foo", 2=>"bar", 3=>"baz", 4=>"blong");var_dump($nonsequential,json_encode($nonsequential));echo PHP_EOL."删除一个连续数组值的方式产生的非连续数组".PHP_EOL;unset($sequential[1]);var_dump($sequential,json_encode($sequential));?>

以上例程会输出：

连续数组array(4) {[0]=>string(3) "foo"[1]=>string(3) "bar"[2]=>string(3) "baz"[3]=>string(5) "blong"}string(27) "["foo","bar","baz","blong"]"非连续数组array(4) {[1]=>string(3) "foo"[2]=>string(3) "bar"[3]=>string(3) "baz"[4]=>string(5) "blong"}string(43) "{"1":"foo","2":"bar","3":"baz","4":"blong"}"删除一个连续数组值的方式产生的非连续数组array(3) {[0]=>string(3) "foo"[2]=>string(3) "baz"[3]=>string(5) "blong"}string(33) "{"0":"foo","2":"baz","3":"blong"}"

$obj->Name= 'a1';$obj->Number ='123';$obj->Contno= '000';echo json_encode($obj);

结果为：

{"Name":"a1","Number":"123","Contno":"000"}