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Unity Engine

EntityId

A unique identifier for a Unity object.
Read time 2 minutesLast updated 8 days ago

Definition

public struct EntityId : IEquatable<EntityId>, IComparable<EntityId>

Remarks

Unity assigns an 
EntityId
to every object it loads or creates, and uses that identifier to refer to the object for as long as the object exists. To get the identifier of an object, use 
Object.GetEntityId
. To resolve an identifier back to an object, use Resources.EntityIdToObject.
The internal representation of 
EntityId
is an implementation detail and might change between versions. To ensure compatibility, avoid the following patterns:
  • Assuming any particular bit layout or sign conventions.
  • Manipulating individual bits of the 
    EntityId
    value.
  • Sorting 
    EntityId
    values to determine creation order.
  • Using 
    Object.GetHashCode
    as a substitute for, or to derive, an 
    EntityId
    .
  • Serializing 
    EntityId
    with 
    ToString
    and deserializing with integer parsing.
To work with 
EntityId
values, use the provided API methods, such as EntityId.IsValid, EntityId.Equals, and EntityId.GetHashCode.
EntityId
converts implicitly to and from 
int
, so existing code that contains object identifiers in integers continues to compile. Store object identity in 
EntityId
fields, parameters, and collection keys rather than in 
int
values, and use the 
EntityId
API instead of integer arithmetic.
Note: Code that previously used 
InstanceID
as an integer should be updated to use the 
EntityId
API methods instead.
Additional Resources: Migrate from InstanceID to EntityId.

Static Properties

Property

Description

NoneGets an EntityId that represents no valid Object or Entity. Use this to indicate an invalid or unassigned identifier.

Methods

Method

Description

CompareToCompares this EntityId to another EntityId.
EqualsDetermines whether the specified integer value is equal to this EntityId.
GetHashCodeReturns a hash code for this EntityId.
IsValidDetermines whether this EntityId is set to a value other than EntityId.None.
ToStringReturns a string representation of this EntityId.

Operators

Operator

Description

operator ==Determines whether two EntityId instances are equal.
operator >Determines whether the first EntityId is greater than the second.
operator >=Determines whether the first EntityId is greater than or equal to the second.
EntityIdImplicitly converts an integer to an 
EntityId
.
intImplicitly converts an 
EntityId
to an integer.
operator !=Determines whether two EntityId instances are not equal.
operator <Determines whether the first EntityId is less than the second.
operator <=Determines whether the first EntityId is less than or equal to the second.