blocks|key|427883|text|可以强制转换为数组，然后检查数组是否为空|type|unstyled|depth|inlineStyleRanges|entityRanges|data|427884|$arr+=+(array)$obj;
if+(!$arr)+{
++++//+do+stuff
}|code-block|syntax|javascript|427885|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 cast to an array and then check if it is empty or not

<pre><code>$arr = (array)$obj;
if (!$arr) {
 // do stuff
}
</code></pre>

blocks|key|428117|text|您可以将对象转换为数组，并测试其计数，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|428118|if(count((array)$obj))+{
+++//+doStuff
}|code-block|syntax|javascript|428119|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 cast your object into an array, and test its count like so:

<pre><code>if(count((array)$obj)) {
 // doStuff
}
</code></pre>

blocks|key|642627|text|想象一下，如果对象不是空的，并且在某种程度上相当大，为什么要浪费资源将其强制转换为数组或序列化它……|type|unstyled|depth|inlineStyleRanges|entityRanges|data|642628|这是我在JavaScript中使用的一个非常简单的解决方案。与前面提到的将对象强制转换为数组并检查其是否为空或将其编码为JSON的解决方案不同，这个简单的函数在执行简单任务所使用的资源方面非常有效。|642629|function+emptyObj(+$obj+)+{
++++foreach+(+$obj+AS+$prop+)+{
++++++++return+FALSE;
++++}

++++return+TRUE;
}|code-block|syntax|javascript|642630|解决方案以一种非常简单的方式工作:如果对象为空，它根本不会进入foreach循环，它将返回true。如果它不为空，它将进入foreach循环并立即返回false，而不是传递整个集合。|offset|length|style|CODE|642631|entityMap^0|0|0|0|19|4|1P|7|23|5|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@$K|U|L|V|M|N]|$K|W|L|X|M|N]|$K|Y|L|Z|M|N]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|10|8|@]|9|@]|A|$]]]|P|$]]

Imagine if the object is not empty and in a way quite big, why would you waste the resources to cast it to array or serialize it...

This is a very easy solution I use in JavaScript. Unlike the mentioned solution that casts an object to array and check if it is empty, or to encode it into JSON, this simple function is very efficient concerning used resources to perform a simple task.

<pre><code>function emptyObj( $obj ) {
 foreach ( $obj AS $prop ) {
 return FALSE;
 }

 return TRUE;
}
</code></pre>

The solution works in a very simple manner: It wont enter a foreach loop at all if the object is empty and it will return <code>true</code>. If it's not empty it will enter the <code>foreach</code> loop and return <code>false</code> right away, not passing through the whole set.

blocks|key|428227|text|当在对象上使用empty()时，它不会像往常一样工作，因为如果声明了__isset()重载方法，它将被调用。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|428228|因此，您可以使用count()+(如果对象是Countable)。|428229|或者通过使用get_object_vars()，例如|428230|get_object_vars($obj)+?+TRUE+:+FALSE;|code-block|syntax|javascript|428231|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/class.countable.php^0|7|7|Y|9|0|8|7|M|9|0|0|6|H|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@$9|14|A|15|1|16]]|E|$]]|$1|H|3|I|5|6|7|17|8|@$9|18|A|19|B|C]]|D|@]|E|$]]|$1|J|3|K|5|L|7|1A|8|@]|D|@]|E|$M|N]]|$1|O|3|-4|5|6|7|1B|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

Using <code>empty()</code> won't work as usual when using it on an object, because the <code>__isset()</code> overloading method will be called instead, if declared.

Therefore you can use <code>count()</code> (if the object is <a href="http://php.net/manual/en/class.countable.php" rel="noreferrer">Countable</a>).

Or by using <code>get_object_vars()</code>, e.g.

<pre><code>get_object_vars($obj) ? TRUE : FALSE;
</code></pre>

blocks|key|428062|text|另一种可能的解决方案是不需要强制转换为array|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|428063|//+test+setup
class+X+{+private+$p+=+1;+}+//+private+fields+only+=>+empty
$obj+=+new+X;
//+$obj->x+=+1;


//+test+wrapped+into+a+function
function+object_empty(+$obj+){
++foreach(+$obj+as+$x+)+return+false;
++return+true;
}


//+inline+test
$object_empty+=+true;
foreach(+$obj+as+$object_empty+){+//+value+ignored+...+
++$object_empty+=+false;+//+...+because+we+set+it+false
++break;
}


//+test++++
var_dump(+$object_empty,+object_empty(+$obj+)+);|code-block|syntax|javascript|428064|entityMap^0|J|5|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Another possible solution which doesn't need casting to <code>array</code>:

<pre><code>// test setup
class X { private $p = 1; } // private fields only =&gt; empty
$obj = new X;
// $obj-&gt;x = 1;


// test wrapped into a function
function object_empty( $obj ){
 foreach( $obj as $x ) return false;
 return true;
}


// inline test
$object_empty = true;
foreach( $obj as $object_empty ){ // value ignored ... 
 $object_empty = false; // ... because we set it false
 break;
}


// test 
var_dump( $object_empty, object_empty( $obj ) );
</code></pre>

blocks|key|642401|text|没有唯一安全的方法来检查对象是否为空|type|unstyled|depth|inlineStyleRanges|entityRanges|data|642402|php的count()首先强制转换为数组，但强制转换可能会产生空数组，这取决于对象是如何实现的(扩展的对象通常会受到这些问题的影响)|642403|在你的例子中，你必须使用$obj->count()；|642404|http://it.php.net/manual/en/simplexmlelement.count.php|offset|length|642405|(这不是php的count+http://www.php.net/count+)|642406|entityMap|0|LINK|mutability|MUTABLE|url|1|http://www.php.net/count^0|0|0|0|0|1I|0|0|E|O|1|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|X|8|@]|9|@$H|Y|I|Z|1|10]]|A|$]]|$1|J|3|K|5|6|7|11|8|@]|9|@$H|12|I|13|1|14]]|A|$]]|$1|L|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|M|$N|$5|O|P|Q|A|$R|G]]|S|$5|O|P|Q|A|$R|T]]]]

there's no unique safe way to check if an object is empty

php's count() first casts to array, but casting can produce an empty array, depends by how the object is implemented (extensions' objects are often affected by those issues)

in your case you have to use $obj->count();

<a href="http://it.php.net/manual/en/simplexmlelement.count.php" rel="nofollow">http://it.php.net/manual/en/simplexmlelement.count.php</a>

(that is not php's count <a href="http://www.php.net/count" rel="nofollow">http://www.php.net/count</a> )

blocks|key|642589|text|如果您在PHP中将任何内容强制转换为(bool)，它将立即告诉您该项是对象、原始类型还是null。使用以下代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|642590|$obj+=+simplexml_load_file($url);

if+(!(bool)$obj)+{
++++print+"This+variable+is+null,+0+or+empty";
}+else+{
++++print+"Variable+is+an+object+or+a+primitive+type!";
}|code-block|syntax|javascript|642591|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 cast anything in PHP as a (bool), it will tell you right away if the item is an object, primitive type or null. Use the following code:

<pre><code>$obj = simplexml_load_file($url);

if (!(bool)$obj) {
 print "This variable is null, 0 or empty";
} else {
 print "Variable is an object or a primitive type!";
}
</code></pre>

blocks|key|428019|text|对象是否为“空”是一个定义问题，因为它取决于类表示的对象的性质，所以由类来定义。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|428020|PHP本身认为类的每个实例都不是空的。|428021|class+Test+{+}
$t+=+new+Test();
var_dump(empty($t));

//+results+in+bool(false)|code-block|syntax|javascript|428022|不能有“空”对象的通用定义。在上面的示例中，您可能会争辩说empty()的结果应该是true，因为该对象不表示任何内容。但是PHP怎么知道呢？有些对象从来不是用来表示内容的(比如工厂)，而其他对象总是表示有意义的值(比如new+DateTime())。|offset|length|style|CODE|428023|简而言之，您必须为特定对象提出自己的标准，并相应地进行测试，无论是从对象外部还是从对象中自编写的isEmpty()方法进行测试。|428024|entityMap^0|0|0|0|T|7|16|4|32|E|0|1C|9|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|V|8|@$K|W|L|X|M|N]|$K|Y|L|Z|M|N]|$K|10|L|11|M|N]]|9|@]|A|$]]|$1|O|3|P|5|6|7|12|8|@$K|13|L|14|M|N]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|R|$]]

If an object is "empty" or not is a matter of definition, and because it depends on the nature of the object the class represents, it is for the class to define.

PHP itself regards every instance of a class as not empty.

<pre><code>class Test { }
$t = new Test();
var_dump(empty($t));

// results in bool(false)
</code></pre>

There cannot be a generic definition for an "empty" object. You might argue in the above example the result of <code>empty()</code> should be <code>true</code>, because the object does not represent any content. But how is PHP to know? Some objects are never meant to represent content (think factories for instance), others always represent a meaningful value (think <code>new DateTime()</code>).

In short, you will have to come up with your own criteria for a specific object, and test them accordingly, either from outside the object or from a self-written <code>isEmpty()</code> method in the object.

blocks|key|428165|text|我在post请求中使用了字符串的json_decode。上述方法对我都不起作用，最后我使用了以下方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|428166|$post_vals+=+json_decode($_POST['stuff']);

if(json_encode($post_vals->object)+!=+'{}')
{
++++//+its+not+empty
}|code-block|syntax|javascript|428167|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|$]]

I was using a json_decode of a string in post request. None of the above worked for me, in the end I used this:

<pre><code>$post_vals = json_decode($_POST['stuff']);

if(json_encode($post_vals-&gt;object) != '{}')
{
 // its not empty
}
</code></pre>

blocks|key|642683|text|$array+=+array_filter($array);
if(!empty($array))+{
++++echo+"not+empty";
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|642684|或|unstyled|642685|if(count($array)+>+0)+{
++++echo+'Error';
}+else+{
++++echo+'No+Error';
}|642686|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|L|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|I|3|-4|5|F|7|N|8|@]|9|@]|A|$]]]|J|$]]

<pre><code>$array = array_filter($array);
if(!empty($array)) {
 echo "not empty";
}
</code></pre>

or

<pre><code>if(count($array) &gt; 0) {
 echo 'Error';
} else {
 echo 'No Error';
}
</code></pre>

blocks|key|428252|text|只需检查对象类型是否为空。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|428253|if(+$obj+!==+null+)
{
+++++//+DO+YOUR+WORK
}|code-block|syntax|javascript|428254|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|$]]

Simply check if object type is null or not.
<pre><code>if( $obj !== null )
{
 // DO YOUR WORK
}
</code></pre>

blocks|key|428274|text|count($the_object)+>+0)这是有效的，也可用于数组|type|unstyled|depth|inlineStyleRanges|entityRanges|data|428275|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

count($the_object) &gt; 0) this is working and can be use for array too

How to find if an object is empty or not in PHP.

Following is the code in which <code>$obj</code> is holding XML data. How can I check if it's empty or not?

My code:

<pre><code>$obj = simplexml_load_file($url);
</code></pre>

How to check that an object is empty in PHP?

如何在PHP中发现一个对象是否为空。下面是$obj保存XML数据的代码。我怎么检查它是不是空的？我的代码：$obj = simplexml_load_file($url);

问如何在PHP中检查对象是否为空？
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