PHP魔术方法__toString()
2018-09-17 19:00 By
"Powerless"
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0
2
注意：该方法必须返回字符串，否则会抛出"E_RECOVERABLE_ERROR"级别的异常。在__toString()方法中也不能抛出异常。
示例代码如下：
<?php
class Person
{
public $sex;
public $name;
public $age;
public function __construct($name="", $age=25, $sex='Male')
{
$this->name = $name;
$this->age = $age;
$this->sex = $sex;
}
public function __toString()
{
return 'go go go';
}
}
$person = new Person('John'); // 赋初始值
echo $person;
输出结果如下：
go go go
如果类中没有定义__toString()会怎样？我们来试试看。
<?php
class Person
{
public $sex;
public $name;
public $age;
public function __construct($name="", $age=25, $sex='Male')
{
$this->name = $name;
$this->age = $age;
$this->sex = $sex;
}
}
$person = new Person('John'); // 赋初始值
echo $person;
输出结果如下：
Catchable fatal error: Object of class Person could not be converted to string in D:\phpStudy\WWW\test\index.php on line 18
可见，它会在页面上报告致命错误，说明这种用法不允许。
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