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C++ Lambda Expressions

Lambda Expressions

C++ lambda expressions use [] for anonymous functions.

Introduction to Lambda Expressions in C++

C++ lambda expressions, introduced in C++11, provide a concise way to define anonymous functions. These expressions are useful for creating short snippets of code that can be passed as arguments to algorithms or other functions.

Basic Syntax of Lambda Expressions

A lambda expression in C++ is defined using the following syntax:

  • []: The capture clause, used to capture variables from the surrounding scope.
  • (): A parameter list, similar to those in regular functions.
  • {}: A function body, containing the code to be executed.

Capturing Variables in Lambda Expressions

Variables from the surrounding scope can be captured by value or by reference. This allows the lambda to access variables not passed in as parameters.

  • By Value: Captures a copy of the variable.
  • By Reference: Captures the variable by reference, allowing modification.

Specifying Return Types

While C++ can often deduce the return type of a lambda, you can specify it explicitly if needed using the trailing return type syntax:

Lambda Expressions with Algorithms

Lambda expressions are particularly useful with standard algorithms. For example, they can be used to define custom sorting criteria:

Conclusion

C++ lambda expressions are a powerful feature that allows developers to write cleaner and more expressive code. They are particularly effective in scenarios involving temporary functions or callbacks. Understanding how to effectively use lambda expressions can greatly enhance your C++ coding practices.

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