Check out example codes for "lambda c++". It will help you in understanding the concepts better.

Code Example 1

#include <iostream>
#include <string>
 
// returns a lambda
auto makeWalrus(const std::string& name)
{
  // Capture name by reference and return the lambda.
  return [&]() {
    std::cout << "I am a walrus, my name is " << name << '\n'; // Undefined behavior
  };
}
 
int main()
{
  // Create a new walrus whose name is Roofus.
  // sayName is the lambda returned by makeWalrus.
  auto sayName{ makeWalrus("Roofus") };
 
  // Call the lambda function that makeWalrus returned.
  sayName();
 
  return 0;
}

Code Example 2

[ capture clause ] (parameters) -> return-type  
{   
   definition of method   
}

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