PHP 从动态生成的字符串调用类实例


php invoke class instance from dynamically generated string

>假设我有一个名为"translations"的类。我有一个名为"chinese_translations"的类实例

$chinese_translations = new translations;

之后,我想从动态构建的字符串调用此实例,并且尝试了几种方法:

$part1 = 'chinese_';
$part2 = 'translations';
$instance_of_translations = ${$part1.$part2};
$instance_of_translations->getMsg();//Doesn't work

也像这样:

$part1 = 'chinese_';
$part2 = 'translations';
$instance_of_translations = $part1.$part2;
$$instance_of_translations->getMsg();//Doesn't work

我总是收到"在非对象上调用成员函数 getMsg()"消息。我做错了什么?

*采取的一些行动和取得的成果:

//Lets see if the var is in scope:
echo $chinese_translations->getMsg(get_locale());//It works
$instance_of_translations = ${$part1.$part2};//Let's try to build the name dynamically
echo $chinese_translations->getMsg(get_locale()); //Call to a member function getMsg() on a non-object
echo $$chinese_translations->getMsg(get_locale()); //Object of class internal_message could not be converted to string in
var_dump($instance_of_translations);//It throws the following:
//object(internal_message)#1956 (1) { ["message"]=> array(2) { ["es_ES"]=> string(19) "The expected result" ["it_IT"]=> string(19) "The expected result" } }NULL
$part1.$part2是一个

字符串。因此,$instance_of_translations是变量名称,而不是变量本身。

试试这个:

$part1 = 'chinese_';
$part2 = 'translations';
$varName = $part1.$part2;
$instance_of_translations = $$varName;
var_dump($instance_of_translations);

它应该显示类型 translations 的对象。

阅读有关变量的更多信息。

试试这个:

$className = $part1.$part2;
$instance = new $$className;
$instance->getMsg();

最后,括号版本起到了作用,但存在范围问题,因此两个答案都可能是正确的。这个:

 $part1 = 'chinese_';
 $part2 = 'translations';
 $instance_of_translations = ${$part1.$part2};
 $instance_of_translations->getMsg();

目前正在为我工作。