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    Method HasComponent

    HasComponent<T>(Entity)

    Checks whether an entity has a specific type of component.

    Declaration
    public static bool HasComponent<T>(Entity entity) where T : unmanaged, IComponentData
    Parameters
    Type Name Description
    Entity entity

    The Entity object.

    Returns
    Type Description
    bool

    True, if the specified entity has the component.

    Type Parameters
    Name Description
    T

    The data type of the component.

    Remarks

    Always returns false for an entity that has been destroyed.

    Use this method to check if another entity has a given type of component using its Entity object. For example, if you have a component that contains an Entity field, you can check whether the referenced entity has a specific type of component using this method. (Entities in the set always have required components, so you don’t need to check for them.)

    When iterating over a set of entities via IJobEntity or Query<T1>(), avoid using this method with the current entity in the set. It is generally faster to change your entity query methods to avoid optional components; this may require a different construction to handle each combination of optional and non-optional components.

    When you call this method this method gets replaced with component access methods through a cached ComponentLookup<T>.

    This lookup method results in a slower, indirect memory access. When possible, organize your data to minimize the need for indirect lookups.

    HasComponent<T>(SystemHandle)

    Checks whether an entity associated with a system has a specific type of component.

    Declaration
    public static bool HasComponent<T>(SystemHandle systemHandle) where T : unmanaged, IComponentData
    Parameters
    Type Name Description
    SystemHandle systemHandle

    The system handle.

    Returns
    Type Description
    bool

    True, if the specified system owned entity has the component.

    Type Parameters
    Name Description
    T

    The data type of the component.

    Remarks

    Always returns false for an system that has been destroyed.

    Use this method to check if another system owned entity has a given type of component using its SystemHandle object.

    When you call this method this method gets replaced with component access methods through a cached ComponentLookup<T>.

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