Typed Properties

When to use

• The user adds explicit types to class properties for stronger contracts on PHP 7.4+.
• The user wants a property that may legitimately hold null, distinct from an unset property, on PHP 7.4+.
• The user declares typed properties through constructor property promotion on PHP 8.0+.

When NOT to use

• Do not force a narrow type when the property genuinely holds heterogeneous or dynamic data; model it as an object or a typed collection instead.
• Do not use typed properties when the target runtime is PHP 7.3 or earlier; document types in docblocks instead.

Core guidance