For Loop

A for loop is useful when code needs an index variable.

for_loop.cpp

#include <iostream>

int main() {
    int values[4] = {3, 5, 7, 9};
    int multiplier = ;
    int total = 0;

    for (int i = 0; i < 4; i++) {
        total += values[i] * multiplier;
    }

    std::cout << "multiplier=" << multiplier << std::endl;
    std::cout << "total=" << total << std::endl;
    return 0;
}

#include <iostream>

int main() {
    int values[4] = {3, 5, 7, 9};
    int multiplier = ;
    int total = 0;

    for (int i = 0; i < 4; i++) {
        total += values[i] * multiplier;
    }

    std::cout << "multiplier=" << multiplier << std::endl;
    std::cout << "total=" << total << std::endl;
    return 0;
}

#include <iostream>

int main() {
    int values[4] = {3, 5, 7, 9};
    int multiplier = ;
    int total = 0;

    for (int i = 0; i < 4; i++) {
        total += values[i] * multiplier;
    }

    std::cout << "multiplier=" << multiplier << std::endl;
    std::cout << "total=" << total << std::endl;
    return 0;
}

indexed loop An indexed loop can use `i` to read each array element by position.