json_decode()とjson_encode()違い------2015-0929

9547 ワード

json_decodeはJSON形式の文字列を符号化しjson_encodeは変数に対してJSONコードを行って、必要な友达は参考にすることができます
 
1.json_decode() json_decode (PHP 5 >= 5.2.0, PECL json >= 1.2.0) json_decode-JSON形式の文字列を符号化する説明mixed json_decode(string$json[,bool$assoc])は、JSON形式の文字列を受け入れ、PHP変数パラメータjsonが復号するjson string形式の文字列に変換する.assocパラメータがTRUEの場合、objectではなくarrayが返されます.戻り値Returns an object or if the optional assoc parameter is TRUE,an associative array is instead returned.サンプルExample#1 json_decode()の例
 
  
<?php
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
var_dump(json_decode($json));
var_dump(json_decode($json, true));
?>

上記の例では、次のように出力されます.
 
  
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)
}

呼び出し時の区別オブジェクトと配列の区別を追加します.
デフォルトではtrueを付けないときに出力されるのはオブジェクトで、参照するときに「->」を使用します.配列の場合は["]
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';$obj=json_decode($json);echo $obj->a;$arr=json_decode($json, true);echo $arr["b"];
 
  
$data='[{"Name":"a1","Number":"123","Contno":"000","QQNo":""},{"Name":"a1","Number":"123","Contno":"000","QQNo":""},{"Name":"a1","Number":"123","Contno":"000","QQNo":""}]';
echo json_decode($data);

結果:
 
  
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] => ) )

json_decode()はオブジェクトをコンパイルし、json_を出力します.decode($data,true)試してみる
 
  
echo json_decode($data,true);

結果:
 
  
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] => ) )

json_がわかりますdecode($data,true)出力の関連配列、
ここからjson_decode($data)はオブジェクトを出力します(注:オブジェクトの参照用->
そしてjson_decode("$arr",true)は、それを強制的にPHP関連配列を生成する.2.json_encode() json_encode (PHP 5 >= 5.2.0, PECL json >= 1.2.0) json_Encode-変数のJSON符号化Report a bug説明string json_Encode(mixed$value[,int$options=0])は、value値のJSON形式Report a bugパラメータvalueが符号化されるvalueを返し、resourceタイプを除いて、UTF-8符号化のみを受け入れるデータoptionsの定数からなるバイナリマスク: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戻り値符号化に成功すると、JSON形式で表されるstringを返すか、失敗したときにFALSEを返す.Report a bug更新ログバージョン説明5.4.0 optionsパラメータ増加定数:JSON_PRETTY_PRINT, JSON_UNESCAPED_SLASHESとJSON_UNESCAPED_UNICODE. 5.3.3 optionsパラメータ増加定数:JSON_NUMERIC_CHECK. 5.3.0 optionsパラメータを追加する.Report a bugサンプルExample#1 A json_Encode()の例
 
  
<?php
$arr = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);

echo json_encode($arr);
?>

以上のルーチンが出力します.
 
  
{"a":1,"b":2,"c":3,"d":4,"e":5}

Example #2 json_Encode()関数におけるoptionsパラメータの使い方
 
  
<?php
$a = array('<foo>',"'bar'",'"baz"','&blong&', "\xc3\xa9");

echo "Normal: ", json_encode($a), "
";
echo "Tags: ", json_encode($a, JSON_HEX_TAG), "
";
echo "Apos: ", json_encode($a, JSON_HEX_APOS), "
";
echo "Quot: ", json_encode($a, JSON_HEX_QUOT), "
";
echo "Amp: ", json_encode($a, JSON_HEX_AMP), "
";
echo "Unicode: ", json_encode($a, JSON_UNESCAPED_UNICODE), "
";
echo "All: ", json_encode($a, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE), "

";

$b = array();

echo "Empty array output as array: ", json_encode($b), "
";
echo "Empty array output as object: ", json_encode($b, JSON_FORCE_OBJECT), "

";

$c = array(array(1,2,3));

echo "Non-associative array output as array: ", json_encode($c), "
";
echo "Non-associative array output as object: ", json_encode($c, JSON_FORCE_OBJECT), "

";

$d = array('foo' => 'bar', 'baz' => 'long');

echo "Associative array always output as object: ", json_encode($d), "
";
echo "Associative array always output as object: ", json_encode($d, JSON_FORCE_OBJECT), "

";
?>

以上のルーチンが出力します.
 
  
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連続と非連続配列の例
 
  
<?php
echo " ".PHP_EOL;  //PHP_EOL  ,  html 
$sequential = array("foo", "bar", "baz", "blong");
var_dump(
$sequential,
json_encode($sequential)
);

echo PHP_EOL." ".PHP_EOL;
$nonsequential = array(1=>"foo", 2=>"bar", 3=>"baz", 4=>"blong");
var_dump(
$nonsequential,
json_encode($nonsequential)
);

echo PHP_EOL." ".PHP_EOL;
unset($sequential[1]);
var_dump(
$sequential,
json_encode($sequential)
);
?>

以上のルーチンが出力します.
 
  

array(4) {
[0]=>
string(3) "foo"
[1]=>
string(3) "bar"
[2]=>
string(3) "baz"
[3]=>
string(5) "blong"
}
string(27) "["foo","bar","baz","blong"]"


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"}"


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);

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

json_がわかりますencode()とjson_decode()はコンパイルと逆コンパイルプロセスであり、jsonはutf-8符号化の文字のみを受け入れるため、json_Encode()のパラメータはutf-8符号化でなければなりません.そうしないと、空の文字またはnullが得られます.
からhttp://www.jb51.net/article/30489.htm