How can I use filter with Java Streams?

Can you explain how to use the filter method in Java Streams?

Sure! The filter method in Java Streams allows you to filter elements based on a given predicate. For example, if you have a list of integers and want to filter out even numbers, you can use it like this: list.stream().filter(n -> n % 2 != 0).collect(Collectors.toList());.

Can you give me more examples of using filter with different data types?

Absolutely! For a list of strings, you can filter out those that start with a specific letter: list.stream().filter(s -> s.startsWith("A")).collect(Collectors.toList()); For a list of objects, say Person, you can filter by age: people.stream().filter(p -> p.getAge() > 18).collect(Collectors.toList());.

What if I want to combine multiple filters?

You can chain multiple filter calls together. For example: list.stream().filter(n -> n > 10).filter(n -> n < 20).collect(Collectors.toList()); This will give you numbers between 10 and 20.

Are there any performance considerations when using filters?

Yes, using multiple filters can impact performance, especially with large datasets. It's often better to combine conditions in a single filter when possible.