Cannot use variable $%pS twice

Description

The use clause of a closure lists the variables imported from the enclosing scope. Each variable can only appear once in that list: importing the same variable twice, whether by value or by reference, is redundant and not allowed.

This is checked at compile time, as the use list is processed.

Example

<?php

function foo() {
    $a = 1;

    return function () use ($a, $a) {
        return $a;
    };
}

?>

Literal Examples

• Cannot use variable $a twice

Alternatives

• Remove the duplicate entry in the use clause.

Changed Behavior

This error may appear following an evolution in behavior, in previous versions. See