PHP RFC: Normalize increment and decrement operators

• Version: 0.1
• Date: 2013-12-19
• Author: Tjerk Meesters (datibbaw@php.net)
• Status: Draft
• First Published at: https://wiki.php.net/rfc/normalize_inc_dec

The current behaviour of increment and decrement operators is not very intuitive:

// booleans
$a = false; ++$a; // bool(false)
$a = true; --$a; // bool(true)
 
// null values
$a = null; --$a; // null
$a = null; ++$a; // int(1)
 
// empty strings
$a = ''; ++$a; // string(1) "1"
 
// non-numeric strings
$a = '12d9'; 
++$a; // string(4) "12e0"
++$a; // float(13)

The following behaviour is proposed:

// booleans
$a = false; ++$a; // bool(true)
$a = true; --$a; // bool(false)
 
// null values
$a = null; --$a; // null
$a = null; ++$a; // null
 
// empty strings
$a = ''; ++$a; // int(1)
 
// non-numeric strings
$a = '12d9'; 
++$a; // string(4) "12e0" + Notice: String increment is deprecated, use str_inc() instead in php shell code on line 1
++$a; // float(13)

Additionally, it makes two new string functions available:

• str_inc($str) - to perform the current string increments.
• str_dec($str) - the string decrement.

Null no longer increments to 1. Booleans couldn't be incremented in the first place, so there should be no breaks.

Next 5.x

Introduce a notice for the current string increment use case. This will help developers spot their usage more easily.

Next major

Removal of string increment using ++ and --.

None.

The changes do not affect the following data types:

• array
• int
• float
• object
• resource

Yay or nay.

Coming soon ...

N/A

Pull Request

The competing proposal:

Alphanumeric Decrement

Keep this updated with features that were discussed on the mail lists.