What is weak reference in Java

Java Interview Questions and Answers (part 1)

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161. What is weak reference in Java

A weak reference is one that does not prevent the referenced object from being garbage collected. You might use them to manage a HashMap to look up a cache of objects. A weak reference is a reference that does not keep the object it refers to alive. A weak reference is not counted as a reference in garbage collection. If the object is not referred to elsewhere as well, it will be garbage collected.

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Other Interview Questions

• What's Java?
• What does a well-written OO program look like?
• Can you have virtual functions in Java?
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• What is similarities/difference between an Abstract class and Interface?
• How to define an Abstract class?
• How to define an Interface?
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• How many methods in the Externalizable interface?
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• How are Observer and Observable used?
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• Name primitive Java types.
• Which class should you use to obtain design information about an object?
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• What is the difference between static and non-static variables?
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• What is the purpose of the File class?
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• What restrictions are placed on method overriding?
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• What is the Set interface?
• How can you force garbage collection?
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