#include <iostream>

#include <math.h>

using namespace std;

/*

Lambda expression allows us to define anonymous function objects. Lambda function is a small function we can write directly in codes. It's useful when we need a quick function without

naming it or declaring it separately.

Syntax:

auto name = [capture] (parameters) {codes};

Note: Like normal functions, lambda expressions can also have a return type.

Example:

int main(){

auto message = [](){cout << "Lambda" << endl;} //Create a lambda function and assign it to a variable name (message) without parameters that prints "Lambda".

message();

}

*/

//Passing lambdas to functions

#include <functional>

void myFunc(function<void()> func){

func();

func();

func();

}

int main(){

auto add = [] (int a, int b){

return a+b;

};

int sum;

sum = add(1234, 4567);

cout << sum << endl;

auto multiple = [] (int a, int b) -> double{

return a*b;

};

int mtp;

mtp = multiple(2222, 3333);

cout << mtp << endl;

cout << endl;

//Lambdas in loops

for (int i=0; i<4; i++){

auto print = [i](){

cout << "Number " << i << endl;

};

print();

}

cout << endl;

//Access to variables outside of lambdas

int num1 = 70;

int num2 = 120;

auto myLambda = [num1, num2](){ //num1 and num2 are read-only

cout << sin(num1) + cos(num2) << endl;

};

myLambda();

cout << endl;

//Using lambdas as an argument

myFunc(myLambda);

}