The lambda function (also known as a lambda expression or simply a lambda) is a powerful feature that allows developers to define an anonymous function object right at the location where the lambda is invoked. Instead of having to create an entire named function for just a handful of lines of code, lambdas encapsulate these lines into an anonymous function object, vastly improving readability.
In this article, we will thoroughly explore the syntax and usage of lambda functions in C++, beginning with simple examples and expanding to more complex and niche examples.
Lambda Basics
The basic syntax of a lambda function looks like this:
[capture](parameters) {
// Function body
}- Capture: The capture clause specifies which variables from the surrounding scope are captured in the lambda and whether they are captured by value or by reference.
- Parameters: Similar to regular function parameters. May be empty.
- Function body: The code that is executed.
The lambda may be anonymous with its definition passed directly into a function as a parameter, or it may be named and stored as a variable for future use. For example, the following examples of using a lambda for a custom comparator for std::sort are both valid:
#include <algorithm>
#include <iostream>
#include <vector>
int main() {
std::vector<int> numsOne{1, 5, 3, 4, 2};
std::vector<int> numsTwo{12, 13, 11…