Definition of strong reference strong and weak reference weak

1. A strong reference represents a dependency, and the reference object owns the referenced object. A weak reference implies that the referenced object does not own the referenced object. The lifetime of an object is determined by how many times it is strongly referenced. The object is not disposed as long as the object has a strong reference.

Note: However, a strong reference loop occurs when a reference between objects is a strong reference, causing the memory leak to occur when the object's memory is not released, and the workaround is that an object uses a strong reference, and an object uses a weak reference because the object is freed when an object is not strongly referenced. All weak references to the object are set to nil .

Definition of strong reference strong and weak reference weak