How is the strategy pattern defined?

In computer programming, the strategy pattern (also known as the policy pattern) is a behavioral software design pattern that enables selecting an algorithm at runtime . Instead of implementing a single algorithm directly, code receives run-time instructions as to which in a family of algorithms to use.

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Why is Java Observer deprecated?

Ans: The Observable class and the Observer interface have been deprecated in Java 9 because the event model supported by Observer and Observable is quite limited, the order of notifications delivered by Observable is unspecified, and state changes are not in one-for-one correspondence with notifications.

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Are event listeners functions?

The EventListener interface represents an object that can handle an event dispatched by an EventTarget object. Note: Due to the need for compatibility with legacy content, EventListener accepts both a function and an object with a handleEvent() property function. This is shown in the example below.

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