What are the scenarios where Lambda expressions are used?

Lambda表达式的应用场景有很多，以下是其中一些常见的应用场景：

1. Functional programming: Lambda expressions are an important feature of functional programming that can be used to replace traditional anonymous inner classes, simplifying code and improving readability.
2. Combining Lambda expressions with collection operation methods (such as forEach, filter, map, reduce) allows for traversing, filtering, mapping, aggregating, and other operations on elements within the collection.
3. Sorting: Lambda expressions can be used for custom sorting functions, allowing for the sorting of elements in a collection by passing different comparison rules.
4. Thread programming: Lambda expressions can be used to simplify code in thread programming, such as creating a Runnable object using Lambda expressions, or implementing functional interfaces with Lambda expressions to handle thread tasks.
5. Lambda expressions can be used to simplify GUI event handling code, such as registering event listeners for buttons, menus, and other components.
6. Data processing: Lambda expressions can be used to process large data sets, such as performing statistics, filtering, and transformation, and their ability to process in parallel can improve the efficiency of data processing.
7. In web development, Lambda expressions can be used to simplify repetitive code, such as implementing controllers, filters, interceptors, etc.

In conclusion, Lambda expressions have a wide range of applications and can be used in any situation where behavior needs to be passed, helping simplify code, improve readability, and maintainability.