classConstant.nameNotString

Code example

<?php declare(strict_types = 1);

class Foo
{
	public const BAR = 'bar';
}

function doFoo(int $name): void
{
	echo Foo::{$name};
}

Why is it reported?

When accessing a class constant dynamically with ClassName::{$expr} (available since PHP 8.3), the expression must evaluate to a string. If the expression has a non-string type such as int, object, or mixed, PHP will throw a TypeError at runtime. In the example above, $name is an int, which is not a valid class constant name.

How to fix it

Ensure the dynamic constant name expression is a string:

 <?php declare(strict_types = 1);

 class Foo
 {
 	public const BAR = 'bar';
 }

-function doFoo(int $name): void
+function doFoo(string $name): void
 {
 	echo Foo::{$name};
 }