In what situations are weak references used in programming?

Weak references in Java are used to refer to objects without preventing their garbage collection. This is useful in the following situations:

• Caching: objects are cached using weak references so they can be removed when memory is low.
• Avoiding memory leaks: when you need to refer to an object but do not want to keep it in memory longer than necessary.
• Listeners and callbacks: to avoid cyclic references that hinder garbage collection.

Example of using a weak reference:

import java.lang.ref.WeakReference;

Object strongRef = new Object();
WeakReference<Object> weakRef = new WeakReference<>(strongRef);

strongRef = null; // now the object is only accessible through weakRef

// The object can be garbage collected if there are no strong references