Using the Lambda expression for multiline functions

The Lambda expression can also be used for multiline functions, so we can put the body of the function on it. This will make our code more readable as well. Let's make a new code. In that code, we will have an integer collection and an intent to inspect whether the selected element is the prime number or not. We can make a separate function, for instance, PrintPrime(), then invoke it. However, since the prime number checking operation is called only once, it's more readable if we transform it into a Lambda expression. The code should look like this:

    /* lambda_multiline_func.cpp */
    #include <vector>
    #include <algorithm>
    #include <iostream>

    using namespace std;

    auto main() -> int
    {
      cout << "[lambda_multiline_func.cpp]" << endl;

      // Initializing a vector containing integer element
      vector<int> vect;
      for (int i = 0; i < 10; ++i)
        vect.push_back(i);

      // Displaying whether or not the element is prime number
      for_each(
             begin(vect),
             end(vect),
             [](int n) {
                cout << n << " is";
                if(n < 2)
                {
                  if(n == 0)
                  cout << " not";
                }
                else
                {
                  for (int j = 2; j < n; ++j)
                    {
                       if (n % j == 0)
                       {
                         cout << " not";
                         break;
                       }
                   }
                 }

                cout << " prime number" << endl;
            });

        return 0;
     }

The output we should see on the screen is as follows:

As we can see in the preceding screenshot, we have successfully identified the prime number by using the Lambda expression.