Migrating from PHP 5.6.x to PHP 7.0.x
PHP Manual

Other Changes

Loosening Reserved Word Restrictions

Globally reserved words as property, constant, and method names within classes, interfaces, and traits are now allowed. This reduces the surface of BC breaks when new keywords are introduced and avoids naming restrictions on APIs.

This is particularly useful when creating internal DSLs with fluent interfaces:

<?php
// 'new', 'private', and 'for' were previously unusable
Project::new('Project Name')->private()->for('purpose here')->with('username here');
?>

The only limitation is that the class keyword still cannot be used as a constant name, otherwise it would conflict with the class name resolution syntax (ClassName::class).

Removal of date.timezone Warning

Previously, a warning was emitted if the date.timezone INI setting had not been set prior to using any date- or time-based functions. Now, this warning has been removed (with date.timezone still defaulting to UTC).


Migrating from PHP 5.6.x to PHP 7.0.x
PHP Manual