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:
<?php $json = '{"a":1,"b":2,"c":3,"d":4,"e":5}'; var_dump(json_decode($json)); var_dump(json_decode($json, true)); ?>
上例将输出：
代码如下:
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) }
代码如下:
$data='[{"Name":"a1","Number":"123","Contno":"000","QQNo":""},{"Name":"a1","Number":"123","Contno":"000","QQNo":""},{"Name":"a1","Number":"123","Contno":"000","QQNo":""}]'; echo json_decode($data);
结果为：
代码如下:
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($data,true)试下
代码如下:
echo json_decode($data,true);
结果：
代码如下:
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
代码如下:
<?php $arr = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5); echo json_encode($arr); ?>
以上例程会输出：
代码如下:
{"a":1,"b":2,"c":3,"d":4,"e":5}
Example #2 json_encode() 函数中 options 参数的用法
代码如下:
<?php $a = array('<foo>',"'bar'",'"baz"','&blong&', "\xc3\xa9"); echo "Normal: ", json_encode($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：
代码如下:
Normal: ["<foo>","'bar'","\"baz\"","&blong&","\u00e9"] Tags: ["\u003Cfoo\u003E","'bar'","\"baz\"","&blong&","\u00e9"] Apos: ["<foo>","\u0027bar\u0027","\"baz\"","&blong&","\u00e9"] Quot: ["<foo>","'bar'","\u0022baz\u0022","&blong&","\u00e9"] Amp: ["<foo>","'bar'","\"baz\"","\u0026blong\u0026","\u00e9"] Unicode: ["<foo>","'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
代码如下:
<?php echo "连续数组".PHP_EOL; $sequential = array("foo", "bar", "baz", "blong"); var_dump( $sequential, json_encode($sequential) ); echo PHP_EOL."非连续数组".PHP_EOL; $nonsequential = array(1=>"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：
代码如下:
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"}"
代码如下:
$obj->Name= 'a1';$obj->Number ='123'; $obj->Contno= '000'; echo json_encode($obj);
结果为：
代码如下:
{"Name":"a1", "Number":"123", "Contno":"000" }
可以看出json_encode()和json_decode()是编译和反编译过程，注意json只接受utf-8编码的字符，所以json_encode()的参数必须是utf-8编码，否则会得到空字符或者null。