"Increment on non-numeric string is deprecated, use str_increment() instead" and empty-string

[staabm]

Description

The following code:

<?php

$s='';
$s++;
var_dump($s);

works without errors on PHP 8.x and renders a deprecation warning since PHP 8.5.x

---

it results in this output:

Deprecated: Increment on non-numeric string is deprecated, use str_increment() instead in /in/8jhPc on line 4

running a empty string thru str_increment() will turn into a error though

Fatal error: Uncaught ValueError: str_increment(): Argument #1 ($string) must not be empty in /in/8jhPc:7
Stack trace:
#0 /in/8jhPc(7): str_increment('')

I think: either the increment-operator should still be allowed on empty-string, or str_increment should support a empty string.

PHP Version

PHP 8.5.0-dev (cli) (built: Aug 24 2025 22:23:16) (NTS)
Copyright (c) The PHP Group
Built by Shivam Mathur
Zend Engine v4.5.0-dev, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.0-dev, Copyright (c), by Zend Technologies

Operating System

macOS

[Girgias]

An empty string is not a numeric string, and I don't think that "string incrementing" an empty strings makes a lot of sense.

I can go through the hassle of creating a dedicated deprecation warning for an empty string to use 0 instead, but I don't think that is going to be very common?

[staabm]

Thats fair.