7.4
- Typed Properties.
- Arrow Functions.
- Numeric Literal Separator – Can use underscores to visually format numbers.
- New magic methods to replace old serialization methods:
__serialize()and__unserialize(). - Covariant Returns and Contravariant Parameters.
- Deprecations
- Ternary Operator Left Associativity deprecated.
5.3
- Namespaces.