cast.string

Code example

<?php declare(strict_types = 1);

$value = (string) new stdClass();

Why is it reported?

The expression being cast to string is of a type that cannot be converted to a string. PHP does not support casting certain types to string unless the class implements the __toString() method. Attempting to cast an object without __toString() to string will result in a fatal error at runtime.

In the example above, stdClass does not implement __toString(), so it cannot be cast to string.

How to fix it

Implement the __toString() method on the class:

 <?php declare(strict_types = 1);

-$value = (string) new stdClass();
+class MyClass
+{
+    public function __toString(): string
+    {
+        return 'my value';
+    }
+}
+
+$value = (string) new MyClass();

Or extract the string value from the object explicitly:

 <?php declare(strict_types = 1);

-$value = (string) new stdClass();
+$obj = new stdClass();
+$obj->name = 'hello';
+$value = $obj->name;