blocks|key|941484|text|不，你不能。不幸的是，php中的布尔型转换是不可修改的，当一个对象转换成布尔型时，它总是会返回true。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|941485|既然您显然有一些要放在控制语句中逻辑，为什么不在对象上定义一个方法(比如"isValid()“)来检查您想要检查的条件，然后替换：|941486|if+($obj)|code-block|syntax|javascript|941487|通过以下方式：|941488|if+($obj->isValid())|941489|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

No, you can't. Unfortunately boolean casting in php is not modifiable, and an object will always return true when converted to a boolean.

Since you clearly have some logic you mean to place in that control statement, why not define a method on your object (say "isValid()" ) that checks the conditions you wish to check, and then replace:

<pre><code>if ($obj)
</code></pre>

with:

<pre><code>if ($obj-&gt;isValid())
</code></pre>

blocks|key|941529|text|您能做的最好的事情就是使用__invoke|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|941530|class+MyObject+{

++++private+$_state;

++++public+function+__construct($state+=+false)+{
++++++++$this->_state+=+$state;
++++}

++++public+function+__invoke()+{
++++++++return+$this->_state;
++++}

}

$true++=+new+MyObject(true);
$false+=+new+MyObject(false);

var_dump($true());+++//+true
var_dump($false());++//+false|code-block|syntax|javascript|941531|entityMap^0|D|8|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|$]]

The best you can do is using <code>__invoke</code>:

<pre><code>class MyObject {

 private $_state;

 public function __construct($state = false) {
 $this-&gt;_state = $state;
 }

 public function __invoke() {
 return $this-&gt;_state;
 }

}

$true = new MyObject(true);
$false = new MyObject(false);

var_dump($true()); // true
var_dump($false()); // false
</code></pre>

blocks|key|941556|text|你可以这样做：(bool)+$yourObject|type|unstyled|depth|inlineStyleRanges|entityRanges|data|941557|将要|941558|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

You can do it like that :
(bool) $yourObject

will

blocks|key|725549|text|您可以对php7使用小的扩展名：https://github.com/p1ncet/obcast。正如您可以从描述中看到的，它允许通过实现新的内部接口Boolable将对象强制转换为boolean：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|725550|$obj+=+new+class+implements+Boolable+{
++++public+$container+=+[];
++++public+function+__toBoolean()+{
++++++++return+count($this->container)+>+0;
++++}
};

var_dump((bool)+$obj);

$obj->container+=+[1];
var_dump((bool)+$obj);|code-block|syntax|javascript|725551|输出：|725552|bool(false)
bool(true)|725553|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/p1ncet/obcast^0|G|W|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]]]

You can use small extension for php7: <a href="https://github.com/p1ncet/obcast" rel="noreferrer">https://github.com/p1ncet/obcast</a>. As you may see from the description, it allows to cast an object to boolean by implementing new internal interface Boolable:

<pre><code>$obj = new class implements Boolable {
 public $container = [];
 public function __toBoolean() {
 return count($this-&gt;container) &gt; 0;
 }
};

var_dump((bool) $obj);

$obj-&gt;container = [1];
var_dump((bool) $obj);
</code></pre>

output:

<pre><code>bool(false)
bool(true)
</code></pre>

blocks|key|941617|text|很抱歉我来晚了，但我刚刚做了一些类似的任务，并做了一些黑客/变通方法。注意调用__toString方法的"$object"模式。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|941618|class+tst+{
++public+$r+=+true;
++function+__toString()+{+return+$this->r+?+"1"+:+"0";+}
}
$object+=+new+tst();
$object->r+=+true;
echo+'<br+/>1:+';
if+("$object")+echo+'true!';+else+echo+'false!';+//+"$object"+becomes+"1"+==+true
//echo+"$object"+?+'true!'+:+'false!';

$object->r+=+false;
echo+'<br+/>0:+';
echo+"$object"+?+'true!'+:+'false!';+//+"$object"+becomes+"0"+==+false|code-block|syntax|javascript|941619|输出：|941620|1:+true!
0:+false!|941621|entityMap^0|13|A|1G|9|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

Sorry for being late, but I just played with similar task and have made some kind of a hack/workaround. Notice <code>"$object"</code> pattern which calls <code>__toString</code> method.

<pre><code>class tst {
 public $r = true;
 function __toString() { return $this-&gt;r ? "1" : "0"; }
}
$object = new tst();
$object-&gt;r = true;
echo '&lt;br /&gt;1: ';
if ("$object") echo 'true!'; else echo 'false!'; // "$object" becomes "1" == true
//echo "$object" ? 'true!' : 'false!';

$object-&gt;r = false;
echo '&lt;br /&gt;0: ';
echo "$object" ? 'true!' : 'false!'; // "$object" becomes "0" == false
</code></pre>

Output: 

<pre><code>1: true!
0: false!
</code></pre>

Consider the following:

<pre><code>class MyClass
{
 private $var1 = "apple";
 private $var2 = "orange";
}

$obj = new MyClass();

if($obj) { 
 // do this
}
else {
 // do that
}
</code></pre>

PHP evaluates my object to true because it has member variables. Can this logic be overridden somehow? In other words, can I have control over what an object of my class will evaluate to when treated as a boolean?

Evaluate object to a boolean

请考虑以下几点：class MyClass{  private $var1 = "apple";  private $var2 = "orange";}$obj = new MyClass();if($obj) {   // do this}else {  // do that}PHP将我的对象求值为true，因为它有...

问将对象求值为布尔值
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