The C++11 standard introduced a new type of loop called the range-based for loop, or the "for each" loop. This loop allows you to iterate over the elements of a container (such as an array, vector, or list) without having to manage an index variable or pointer.

Here's the syntax of a range-based for loop:

for (type var : container) {
    // Code to execute for each element in the container
}

In this syntax, type is the data type of the elements in the container, var is a variable that will hold each element of the container in turn, and container is the container you want to iterate over.

Here's an example of using a range-based for loop to iterate over the elements of a vector:

#include <vector>
#include <iostream>

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

    for (int n : numbers) {
        std::cout << n << std::endl;
    }

    return 0;
}

In this example, the range-based for loop iterates over each element in the numbers vector, and assigns the value of each element to the variable n. The code inside the loop then prints the value of n to the console.

The output of this code will be:

1
2
3
4
5

The range-based for loop is a convenient and easy-to-read way to iterate over the elements of a container. It can simplify your code and make it more expressive.