blocks|key|1237326|text|php.net说这是最好的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1237327|$new_empty_object+=+new+stdClass();|code-block|syntax|javascript|1237328|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

php.net said it is best:

<pre><code>$new_empty_object = new stdClass();
</code></pre>

blocks|key|1237446|text|除了僵尸的答案，如果你一直忘记stdClass|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1237447|+++function+object(){

++++++++return+new+stdClass();

++++}|code-block|syntax|javascript|1237448|现在您可以执行以下操作：|1237449|$str='';
$array=array();
$object=object();|1237450|entityMap^0|F|8|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

In addition to zombat's answer if you keep forgetting <code>stdClass</code>

<pre><code> function object(){

 return new stdClass();

 }
</code></pre>

Now you can do:

<pre><code>$str='';
$array=array();
$object=object();
</code></pre>

blocks|key|1452460|text|您可以使用new+stdClass()+(推荐)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1452461|$obj_a+=+new+stdClass();
$obj_a->name+=+"John";
print_r($obj_a);

//+outputs:
//+stdClass+Object+(+[name]+=>+John+)+|code-block|syntax|javascript|1452462|或者，您可以将一个空数组转换为一个对象，该对象生成stdClass内置类的一个新的空实例：|1452463|$obj_b+=+(object)+[];
$obj_b->name+=+"John";
print_r($obj_b);

//+outputs:+
//+stdClass+Object+(+[name]+=>+John+)++|1452464|或者，您可以将null值转换为一个对象，该对象将生成stdClass内置类的新的空实例：|1452465|$obj_c+=+(object)+null;
$obj_c->name+=+"John";
print($obj_c);

//+outputs:
//+stdClass+Object+(+[name]+=>+John+)+|1452466|entityMap^0|5|E|0|0|0|0|7|4|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|S|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|T|$]]

You can use <code>new stdClass()</code> (which is recommended):

<pre><code>$obj_a = new stdClass();
$obj_a-&gt;name = "John";
print_r($obj_a);

// outputs:
// stdClass Object ( [name] =&gt; John ) 
</code></pre>

Or you can convert an empty array to an object which produces a new empty instance of the stdClass built-in class:

<pre><code>$obj_b = (object) [];
$obj_b-&gt;name = "John";
print_r($obj_b);

// outputs: 
// stdClass Object ( [name] =&gt; John ) 
</code></pre>

Or you can convert the <code>null</code> value to an object which produces a new empty instance of the stdClass built-in class:

<pre><code>$obj_c = (object) null;
$obj_c-&gt;name = "John";
print($obj_c);

// outputs:
// stdClass Object ( [name] =&gt; John ) 
</code></pre>

blocks|key|1237726|text|使用泛型对象并将键值对映射到它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1237727|$oVal+=+new+stdClass();
$oVal->key+=+$value|code-block|syntax|javascript|1237728|或者将数组转换为对象|1237729|$aVal+=+array(+'key'=>'value'+);
$oVal+=+(object)+$aVal;|1237730|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Use a generic object and map key value pairs to it.

<pre><code>$oVal = new stdClass();
$oVal-&gt;key = $value
</code></pre>

Or cast an array into an object

<pre><code>$aVal = array( 'key'=&gt;'value' );
$oVal = (object) $aVal;
</code></pre>

blocks|key|1237494|text|要以与关联数组类似的方式访问stdClass中的数据，只需使用{$var}语法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1237495|$myObj+=+new+stdClass;
$myObj->Prop1+=+"Something";
$myObj->Prop2+=+"Something+else";

//+then+to+acces+it+directly

echo+$myObj->{'Prop1'};
echo+$myObj->{'Prop2'};

//+or+what+you+may+want

echo+$myObj->{$myStringVar};|code-block|syntax|javascript|1237496|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

to access data in a stdClass in similar fashion you do
with an asociative array just use the {$var} syntax.

<pre><code>$myObj = new stdClass;
$myObj-&gt;Prop1 = "Something";
$myObj-&gt;Prop2 = "Something else";

// then to acces it directly

echo $myObj-&gt;{'Prop1'};
echo $myObj-&gt;{'Prop2'};

// or what you may want

echo $myObj-&gt;{$myStringVar};
</code></pre>

blocks|key|1452193|text|正如其他人所指出的，您可以使用stdClass。然而，我认为没有()会更干净，就像这样：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1452194|$obj+=+new+stdClass;|code-block|syntax|javascript|1452195|然而，基于这个问题，似乎你真正想要的是能够动态地向对象添加属性。您不需要为此使用stdClass，尽管您可以这样做。实际上，你可以使用任何类。只需创建任意类的对象实例并开始设置属性即可。我喜欢创建自己的类，它的名称是o，具有一些基本的扩展功能，我喜欢在这些情况下使用这些功能，并且可以很好地从其他类扩展。基本上，它是我自己的基本对象类。我还希望有一个简单命名为o()的函数。如下所示：|1452196|class+o+{
++//+some+custom+shared+magic,+constructor,+properties,+or+methods+here
}

function+o()+{
++return+new+o;
}|1452197|如果您不想拥有自己的基本对象类型，可以简单地让o()返回一个新的stdClass。O的一个优点是比stdClass更容易记忆，而且更短，无论您是将它用作类名、函数名，还是同时用作两者。即使您的o类中没有任何代码，它仍然比笨拙地大写和命名为stdClass+(这可能会引发“性传播疾病类”的概念)更容易记忆。如果您确实定制了o类，您可能会发现o()函数而不是构造函数语法的用法。它是一个返回值的普通函数，它的限制比构造函数少。例如，函数名可以作为字符串传递给接受可调用参数的函数。函数也支持链接。所以你可以这样做：$result=+o($internal_value)->some_operation_or_conversion_on_this_value()；|1452198|对于一个基础的“语言”来说，这是一个很好的开始，可以在其上构建其他语言层，顶层是用完整的内部DSL编写的。这类似于lisp开发风格，PHP对它的支持比大多数人意识到的要好得多。我知道这有点离题，但这个问题触及了我认为的充分利用PHP功能的基础。|1452199|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

As others have pointed out, you can use stdClass. However I think it is cleaner without the (), like so:

<pre><code>$obj = new stdClass;
</code></pre>

However based on the question, it seems like what you really want is to be able to add properties to an object on the fly. You don't need to use stdClass for that, although you can. Really you can use any class. Just create an object instance of any class and start setting properties. I like to create my own class whose name is simply o with some basic extended functionality that I like to use in these cases and is nice for extending from other classes. Basically it is my own base object class. I also like to have a function simply named o(). Like so:

<pre><code>class o {
 // some custom shared magic, constructor, properties, or methods here
}

function o() {
 return new o;
}
</code></pre>

If you don't like to have your own base object type, you can simply have o() return a new stdClass. One advantage is that o is easier to remember than stdClass and is shorter, regardless of if you use it as a class name, function name, or both. Even if you don't have any code inside your o class, it is still easier to memorize than the awkwardly capitalized and named stdClass (which may invoke the idea of a 'sexually transmitted disease class'). If you do customize the o class, you might find a use for the o() function instead of the constructor syntax. It is a normal function that returns a value, which is less limited than a constructor. For example, a function name can be passed as a string to a function that accepts a callable parameter. A function also supports chaining. So you can do something like:
$result= o($internal_value)->some_operation_or_conversion_on_this_value();

This is a great start for a base "language" to build other language layers upon with the top layer being written in full internal DSLs. This is similar to the lisp style of development, and PHP supports it way better than most people realize. I realize this is a bit of a tangent for the question, but the question touches on what I think is the base for fully utilizing the power of PHP.

blocks|key|1237536|text|如果您想创建具有动态属性的对象(如javascript中的对象)，而不会收到未定义属性的警告。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1237537|class+stdClass+{

public+function+__construct(array+$arguments+=+array())+{
++++if+(!empty($arguments))+{
++++++++foreach+($arguments+as+$property+=>+$argument)+{
++++++++++++if(is_numeric($property)):
++++++++++++++++$this->{$argument}+=+null;
++++++++++++else:
++++++++++++++++$this->{$property}+=+$argument;
++++++++++++endif;
++++++++}
++++}
}

public+function+__call($method,+$arguments)+{
++++$arguments+=+array_merge(array("stdObject"+=>+$this),+$arguments);+//+Note:+method+argument+0+will+always+referred+to+the+main+class+($this).
++++if+(isset($this->{$method})+&&+is_callable($this->{$method}))+{
++++++++return+call_user_func_array($this->{$method},+$arguments);
++++}+else+{
++++++++throw+new+Exception("Fatal+error:+Call+to+undefined+method+stdObject::{$method}()");
++++}
}

public+function+__get($name){
++++if(property_exists($this,+$name)):
++++++++return+$this->{$name};
++++else:
++++++++return+$this->{$name}+=+null;
++++endif;
}

public+function+__set($name,+$value)+{
++++$this->{$name}+=+$value;
}

}

$obj1+=+new+stdClass(['property1','property2'=>'value']);+//assign+default+property
echo+$obj1->property1;//null
echo+$obj1->property2;//value

$obj2+=+new+stdClass();//without+properties+set
echo+$obj2->property1;//null|code-block|syntax|javascript|1237538|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If you want to create object (like in javascript) with dynamic properties, without receiving a warning of undefined property.

<pre><code>class stdClass {

public function __construct(array $arguments = array()) {
 if (!empty($arguments)) {
 foreach ($arguments as $property =&gt; $argument) {
 if(is_numeric($property)):
 $this-&gt;{$argument} = null;
 else:
 $this-&gt;{$property} = $argument;
 endif;
 }
 }
}

public function __call($method, $arguments) {
 $arguments = array_merge(array("stdObject" =&gt; $this), $arguments); // Note: method argument 0 will always referred to the main class ($this).
 if (isset($this-&gt;{$method}) &amp;&amp; is_callable($this-&gt;{$method})) {
 return call_user_func_array($this-&gt;{$method}, $arguments);
 } else {
 throw new Exception("Fatal error: Call to undefined method stdObject::{$method}()");
 }
}

public function __get($name){
 if(property_exists($this, $name)):
 return $this-&gt;{$name};
 else:
 return $this-&gt;{$name} = null;
 endif;
}

public function __set($name, $value) {
 $this-&gt;{$name} = $value;
}

}

$obj1 = new stdClass(['property1','property2'=&gt;'value']); //assign default property
echo $obj1-&gt;property1;//null
echo $obj1-&gt;property2;//value

$obj2 = new stdClass();//without properties set
echo $obj2-&gt;property1;//null
</code></pre>

blocks|key|1452491|text|您也可以尝试这种方式。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1452492|<?php
+++++$obj+=+json_decode("{}");+
+++++var_dump($obj);
?>|code-block|syntax|javascript|1452493|输出：|1452494|object(stdClass)#1+(0)+{+}|1452495|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You can try this way also.

<pre><code>&lt;?php
 $obj = json_decode("{}"); 
 var_dump($obj);
?&gt;
</code></pre>

Output:

<pre><code>object(stdClass)#1 (0) { }
</code></pre>

blocks|key|1452536|text|这里有一个迭代的例子：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1452537|<?php
$colors+=+(object)[];
$colors->red+=+"#F00";
$colors->slateblue+=+"#6A5ACD";
$colors->orange+=+"#FFA500";

foreach+($colors+as+$key+=>+$value)+:+?>
++++<p+style="background-color:<?=+$value+?>">
++++++++<?=+$key+?>+->+<?=+$value+?>
++++
<?php+endforeach;+?>|code-block|syntax|javascript|1452538|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here an example with the iteration:

<pre><code>&lt;?php
$colors = (object)[];
$colors-&gt;red = "#F00";
$colors-&gt;slateblue = "#6A5ACD";
$colors-&gt;orange = "#FFA500";

foreach ($colors as $key =&gt; $value) : ?&gt;
 &lt;p style="background-color:&lt;?= $value ?&gt;"&gt;
 &lt;?= $key ?&gt; -&gt; &lt;?= $value ?&gt;
 &lt;/p&gt;
&lt;?php endforeach; ?&gt;
</code></pre>

blocks|key|1237803|text|stdClass是默认的PHP对象。stdClass没有属性、方法或父级。它不支持魔术方法，也不实现任何接口。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1237804|当您将标量或数组强制转换为Object时，您将获得stdClass的实例。无论何时需要通用对象实例，都可以使用stdClass。|1237805|<?php
//+ways+of+creating+stdClass+instances
$x+=+new+stdClass;
$y+=+(object)+null;++++++++//+same+as+above
$z+=+(object)+'a';+++++++++//+creates+property+'scalar'+=+'a'
$a+=+(object)+array('property1'+=>+1,+'property2'+=>+'b');
?>|code-block|syntax|javascript|1237806|stdClass不是基类！PHP类不会自动从任何类继承。所有类都是独立的，除非它们显式地扩展另一个类。在这方面，PHP不同于许多面向对象的语言。|1237807|<?php
//+CTest+does+not+derive+from+stdClass
class+CTest+{
++++public+$property1;
}
$t+=+new+CTest;
var_dump($t+instanceof+stdClass);++++++++++++//+false
var_dump(is_subclass_of($t,+'stdClass'));++++//+false
echo+get_class($t)+.+"\n";+++++++++++++++++++//+'CTest'
echo+get_parent_class($t)+.+"\n";++++++++++++//+false+(no+parent)
?>|1237808|不能在代码中定义名为“stdClass”的类。该名称已被系统使用。您可以定义一个名为'Object‘的类。|1237809|您可以定义一个扩展stdClass的类，但是您不会得到任何好处，因为stdClass什么也不做。|1237810|(在PHP+5.2.8上测试)|1237811|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|Z|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|6|7|11|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

stdClass is the default PHP object. stdClass has no properties, methods or parent. It does not support magic methods, and implements no interfaces.

When you cast a scalar or array as Object, you get an instance of stdClass. You can use stdClass whenever you need a generic object instance.

<pre><code>&lt;?php
// ways of creating stdClass instances
$x = new stdClass;
$y = (object) null; // same as above
$z = (object) 'a'; // creates property 'scalar' = 'a'
$a = (object) array('property1' =&gt; 1, 'property2' =&gt; 'b');
?&gt;
</code></pre>

stdClass is NOT a base class! PHP classes do not automatically inherit from any class. All classes are standalone, unless they explicitly extend another class. PHP differs from many object-oriented languages in this respect.

<pre><code>&lt;?php
// CTest does not derive from stdClass
class CTest {
 public $property1;
}
$t = new CTest;
var_dump($t instanceof stdClass); // false
var_dump(is_subclass_of($t, 'stdClass')); // false
echo get_class($t) . "\n"; // 'CTest'
echo get_parent_class($t) . "\n"; // false (no parent)
?&gt;
</code></pre>

You cannot define a class named 'stdClass' in your code. That name is already used by the system. You can define a class named 'Object'.

You could define a class that extends stdClass, but you would get no benefit, as stdClass does nothing.

(tested on PHP 5.2.8)

blocks|key|1237349|text|你有一个不好但有用的技术：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1237350|$var+=+json_decode(json_encode([]),+FALSE);|code-block|syntax|javascript|1237351|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You have this bad but usefull technic:

<pre><code>$var = json_decode(json_encode([]), FALSE);
</code></pre>

blocks|key|1237826|text|您也可以通过解析JSON来获取空对象：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1237827|$blankObject=+json_decode('{}');|code-block|syntax|javascript|1237828|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can also get an empty object by parsing JSON:
<pre><code>$blankObject= json_decode('{}');
</code></pre>

with a new array I do this:

<pre><code>$aVal = array();

$aVal[key1][var1] = "something";
$aVal[key1][var2] = "something else";
</code></pre>

Is there a similar syntax for an object

<pre><code>(object)$oVal = "";

$oVal-&gt;key1-&gt;var1 = "something";
$oVal-&gt;key1-&gt;var2 = "something else";
</code></pre>

How to define an empty object in PHP

JSON

对于一个新的数组，我这样做：$aVal = array();$aVal[key1][var1] = "something";$aVal[key1][var2] = "something else";对象是否有类似的语法？(object)$oVal = "";$oVal->key1->var1 = "something";$oVal->key1->var2 = "something else";

问如何在PHP中定义空对象
EN

回答 12

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何在PHP中定义空对象EN

回答 12

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何在PHP中定义空对象
EN