propertyFlags

PropertyFlags is a generic term for a collection of boolean attributes attached to a property or field of an object. Each flag denotes a particular trait, such as readability, writability, enumerability, visibility, persistence, or participation in serialization, replication, or tooling processes. In practice, property flags are usually implemented as a bit field: a numeric value where each bit corresponds to a flag. A flags enumeration defines the available flags, and bitwise operations combine or test them.

Common usage involves defining constants for each flag, for example FLAG_READABLE = 0x01, FLAG_WRITABLE = 0x02, FLAG_ENUMERABLE = 0x04, FLAG_PERSISTENT = 0x08, and so on. The composite propertyFlags variable stores the combination. Testing a flag uses a bitwise AND; enabling or disabling uses bitwise OR or AND with the complement.

Examples appear across programming environments. In C#, a Flags enum named PropertyFlags can be used to annotate metadata on properties. In JavaScript, property descriptors manage attributes like configurable, enumerable, and writable through internal flags. In game engines such as Unreal Engine, property flags (EPropertyFlags) drive editor visibility, replication, serialization, and editing rules on properties declared with UPROPERTY.

Considerations include careful naming to keep flags orthogonal, documenting each flag’s meaning, and planning for extension to avoid breaking existing code. Bit-flag representations offer compact storage and fast checks but can reduce readability if overused.

See also: bit flag, bitmask, property attribute, descriptor.