代码php中json_decode()和json_encode()的使用方法

php中json_decode()和json_encode()的

使用方法

1.json_decode()json_decode

(PHP 5>=5.2.0,PECLjson>=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。as soc

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 insteadr eturne d.

范例

Example#1 json_decode()的例子

复制代码代码如下:

<?p hp

$json='{"a":1var_dump(json_dec ode($json));var_dump(js on_dec ode($js on, true));

?>

上例将输出

复制代码代码如下: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)

}

复制代码代码如下:

$data='[{"Name":"a1"23"":""}]' ;echo json_decode($data);

结果为

复制代码代码如下:

Array( [0]=>stdClas s Object ( [Name]=>a1 [Number]=>123 [Contno]=>000[QQNo]=>)

[1]=>stdClas s Object ( [Name]=>a1 [Number]=>123 [Contno]=>000[QQNo]=>) [2]=>stdClas s Object ( [Name]=>a1 [Number]=>123 [Contno]=>000[QQNo]=>) )

可以看出经过json_dec ode()编译出来的是对象,现在输出json_dec ode($data,true)试下复制代码代码如下:echo json_dec ode($data,true);

结果

复制代码代码如下:

Array( [0]=>Array( [Name]=>a 1 [Numb er]=>123 [Contno]=>000 [Q QNo]=>) [1]=>Array( [Name]=>a 1 [Numb er]=>123[Contno]=>000[Q QNo]=>) [2]=>Array( [Name]=>a 1 [Numb er]=>123 [Contno]=>000[Q QNo]=>) )

可以看出json_dec ode($data,true)输出的一个关联数组,由此可知json_dec ode($data输出的是对象,而js on_dec ode("$arr",true)是把它强制生成PHP关联数组.

2.json_enc ode()

json_enc ode

(PHP 5>=5.2.0,PECLjson>=1.2.0)js on_enc ode—对变量进行JSON编码

Report a bug说明string json_enc ode(mixed$value [, int$options=0] )

返回value值的J SON形式

Report a bug参数value

待编码的value 除了res ourc e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, J SON_HEX_TAG, J SON_HEX_AMP,J S ON_HEX_AP O S, J S ON_NUME RI C_C HEC K, J S ON_PRET TY_PRINT,JSON_UNESCAP ED_SLAS HES, JSON_FORCE_OBJECT, JSON_UNESCAPED_UNICOD E.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_UNESCAP ED_SLAS HES,和J SON_UNESCAP ED_UNICOD E。

5.3.3 options参数增加常量 J S ON_NUMERIC_C HECK。

5.3.0增加options参数.

Report a bug范例

Example#1 A json_encode()的例子

复制代码代码如下:

<?p hp

$arr=array('a'=>1);echo json_encode($arr);

?>

以上例程会输出

复制代码代码如下:

{"a":1}

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

复制代码代码如下:

<?p hp

$a=array('<fo o>'");echo"Normal: ", json_encode($a), "\n";echo"Tags: ", js on_enc ode($a,J SON_HEX_TAG), "\n";echo"Apos: ", json_enc ode($a, JSON_HEX_APOS), "\n";echo"Quot: ", json_encode($a,JSON_HEX_QUOT), "\n";echo"Amp: ", js on_enc ode($a,J SON_HEX_AMP), "\n";echo"Unic ode: ", json_enc ode($a, JSON_UNES CAPED_UNICO DE), "\n";echo "All: ", json_encode($a, JSON_HEX_TAG| JSON_HEX_APOS | JSON_HEX_QUOT |J S ON_HEX_AMP| J S ON_UNES C AP ED_UNICOD E), "\n\n";

$b=array();echo"Empty array output as array: ", json_enc ode($b), "\n";echo"Empty array output as object: ", json_enc ode($b,JSON_FORCE_OBJECT), "\n\n";$c=array(array(1,2,3));echo"Non-as sociative 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

复制代码代码如下:

Normal: ["<foo>","'bar'","\"b az\"","&b long&","\u00e9"]

Tags: ["\u003 Cfoo\u003E","'bar'","\"baz\"","&b long&","\u00 e9"]

Apos: ["<foo>","\u0027bar\u0027","\"baz\"","&b long&","\u00e9"]

Quot: ["<foo>","'bar'","\u0022baz\u0022","&b long&","\u00e9"]

Amp: ["<foo>","'bar'","\"baz\"","\u0026blong\u0026","\u00e9"]

Unicode: ["<foo>","'bar'","\"baz\"","&blong&","é"]

All: ["\u003Cfoo\u003E","\u0027bar\u0027","\u0022baz\u0022","\u0026b long\u0026","é"]Empty array output as array: []

Empty array output as object: {}

Non-as soc iative array output as array: [[1,2,3]]

Non-as sociative 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"}

Examp le#3连续与非连续数组示例

复制代码代码如下:

<?p hpecho"连续数组".PHP_EOL;

$s equential=array("foo", "bar", "baz", "b long");v ar_dump(

$s equential,js on_enc ode($s equential)

);echo PHP_EOL."非连续数组".PHP_EOL;

$nons equential=array(1=>"foo",2=>"bar", 3=>"baz",4=>"blong");v ar_dump(

$nons equwww.s hanxiw ang.netential,js on_enc ode($nons equential)

);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;uns et($s equential[1]);v ar_dump(

$s equential,js on_enc ode($s equential)

);

?>

以上例程会输出

复制代码代码如下:

连续数组

array(4) {

[0]=>string(3) "foo"

[1]=>string(3) "bar"

[2]=>s tring(3) "b az"

[3]=>string(5) "blong"

}string(27) "["foo","bar","baz","b long"]"

非连续数组array(4) {

[1]=>string(3) "foo"

[2]=>string(3) "bar"

[3]=>s tring(3) "b az"

[4]=>string(5) "blong"

}string(43) "{"1":"foo","2":"bar","3":"b az","4":"b long"}"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]=>s tring(3) "b az"

[3]=>string(5) "blong"

}string(33) "{"0":"foo","2":"baz","3":"b long"} "

复制代码代码如下:

$obj->Name='a 1';$obj->Number='123' ;

$obj->C ontno='000' ;echo json_encode($obj);

结果为

复制代码代码如下:

{"Name":"a1"

"Numb er":"123"

"C ontno":"000"

}

可以看出json_enc ode()和json_dec ode()是编译和反编译过程注意json只接受utf-8编码的字符所以js on_enc ode()的参数必须是utf-8编码否则会得到空字符或者null。