PHP: Create a new class object directly from a string return value (string literal)

Question

Is there any possibility to create a new object by a string that is returned by a function or method in PHP? Like some escape method I do not know?

Non-working example:

new ($class->method())();
new "stringliteral"();
new ($class = $class->method())();

Why would you need to use a string literal? Why write new "stringliteral"() instead of new stringliteral()? — Barmar
– Barmar, Commented Oct 23, 2015 at 9:48
See php.net/manual/en/language.namespaces.dynamic.php for the ways to work with class and namespace names dynamically. It looks like they have to be in variables. — Barmar
– Barmar, Commented Oct 23, 2015 at 9:50
Why do you have to do it directly? Is your server running low on variables? — Barmar
– Barmar, Commented Oct 23, 2015 at 10:08
I do not have to do it directly. The question has a more 'informative' character. — lsblsb
– lsblsb, Commented Oct 26, 2015 at 10:14
Would be nice if you'd accept Barmar's answer: stackoverflow.com/a/33299656/1402176 — jakub_jo
– jakub_jo, Commented Oct 12, 2018 at 8:42

Barmar · Accepted Answer · 2015-10-23 10:18:53Z

6

You can do it using ReflectionClass

function makeRef($className) {
    return new ReflectionClass($className);
}
$obj = makeRef($class->method())->newInstance();

In PHP 5.4+ you can turn this into a one-liner:

$obj = (new ReflectionClass($class->method()))->newInstance();

edited Oct 23, 2015 at 10:18

answered Oct 23, 2015 at 10:00

Barmar

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4 Comments

toster-cx Over a year ago

Or if you prefer one-liners $object = (new ReflectionClass($class->method()))->newInstance();. I don't see why one wouldn't just use a variable tho?

Barmar Over a year ago

@toster-cx I tried doing that but got a parse error. Maybe because I'm using PHP 5.3, I suspect it works in PHP 5.4.

lsblsb Over a year ago

Nice thought! Forgot Reflection. Thanks.

lsblsb Over a year ago

Although I do not know the syntax you are using. But since I use a static method now, I can use: (new ReflectionMethod('class', 'method'))->invoke(null, 'param1')

Yvon Huynh · Accepted Answer · 2015-10-23 09:24:07Z

0

Do you want dynamic class creation? here is a read : http://docstore.mik.ua/orelly/webprog/pcook/ch07_13.htm

While it is OK to invoke dynamic function, doing it for class seems to be a stunt.

answered Oct 23, 2015 at 9:24

Yvon Huynh

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1 Comment

lsblsb Over a year ago

no. my question is, if it is possible to create a class directly from a string literal or return value without putting it into a variable before.

ManiMuthuPandi · Accepted Answer · 2015-10-23 09:31:35Z

-1

Yes it is possible. Assign the string to a variable then create object using that variable.

Ex.

<?php
class stringliteral{
  function __construct()
  {
    echo"called";
  }
}
function dumyFunc()
{
  return 'stringliteral';
}
$str=dumyFunc();
if(class_exists($str))
$obj=new $str();
?>

edited Oct 23, 2015 at 9:31

answered Oct 23, 2015 at 9:21

ManiMuthuPandi

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10 Comments

lsblsb Over a year ago

Please read the heading - "directly". I know that I can use a variable.

RiggsFolly Over a year ago

Errrr Fatal error: Class 'stringliteral' not found Think before you jump new instantiates an existing class!!

ManiMuthuPandi Over a year ago

Now it will solve your requirements. check it once again

lsblsb Over a year ago

This doesn't answer the question.

lsblsb Over a year ago

@ManiMuthuPandi: I suggest you delete your answer, because it absolutely doesn't answer my question.

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