The power of C++ lambda expressions

Lambda expression is a type of anonymous function object that provides a concise and flexible way to define small functions. Advantages include: concise and easy to read, can be embedded in code blocks, improves readability, can be used as parameters of higher-order functions, and enhances programming capabilities

C Lambda expression The power of

Lambda expressions are a syntax construct introduced in C++11 that allow developers to define anonymous function objects. Compared with traditional functions, Lambda expressions provide a concise and flexible method, especially suitable for small functions that need to be used once.

Syntax of Lambda expressions

Lambda expressions are defined using the following syntax:

[ capture-list ] (parameter-list) -> return-type { function-body }

• capture-list:Optional part used to specify external variables that lambda expressions can access.
• parameter-list: The parameter list accepted by the lambda expression, similar to a regular function.
• return-type: Optional part, only required when the lambda expression returns a non-void value.
• function-body: The code block to be executed.

Advantages of lambda expressions

Lambda expressions provide many advantages:

• Conciseness:lambda expressions are more concise than traditional functions and easier to write and read.
• Flexible: lambda expressions can be easily embedded within other blocks of code, improving code readability and maintainability.
• Higher-order functions: lambda expressions can be passed as arguments to higher-order functions, such as std::sort and std::find , thus providing more powerful programming capabilities.

Practical case

The following is a practical case using lambda expression to demonstrate how to sort a set of integers:

#include <iostream>
#include <algorithm>
#include <vector>

int main() {
    std::vector<int> numbers = {4, 2, 6, 1, 5, 3};

    // 使用 lambda 表达式对集合进行排序
    std::sort(numbers.begin(), numbers.end(), [](const int& a, const int& b) {
        return a < b;
    });

    // 打印排序后的集合
    for (const int& num : numbers) {
        std::cout << num << ' ';
    }
    std::cout << '\n';

    return 0;
}

In this example, a lambda expression is used as the sorting criterion for the std::sort function. A lambda expression receives two integers as arguments and returns true if the first argument is less than the second argument, and false otherwise. This will sort the elements in the numbers collection in ascending order.

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