ลูป: for, while และ do-while

#include <stdio.h>

int main(void) {
    /* for: start; condition; step */
    for (int i = 1; i <= 5; i++) {
        printf("%d ", i);
    }
    printf("\n");

    /* while: repeat as long as the condition holds */
    int n = 20;
    int steps = 0;
    while (n > 1) {
        n /= 2;
        steps++;
    }
    printf("halved %d times\n", steps);

    /* do-while: the body runs at least once */
    int tries = 0;
    do {
        tries++;
    } while (tries < 3);
    printf("tries = %d\n", tries);

    /* break leaves the loop, continue skips to the next round */
    for (int i = 1; i <= 10; i++) {
        if (i % 2 == 0) continue;
        if (i > 7) break;
        printf("%d ", i);
    }
    printf("\n");
    return 0;
}

#include <iostream>
#include <vector>

int main() {
    // for: start; condition; step
    for (int i = 1; i <= 5; i++) {
        std::cout << i << ' ';
    }
    std::cout << '\n';

    // while: repeat as long as the condition holds
    int n = 20;
    int steps = 0;
    while (n > 1) {
        n /= 2;
        steps++;
    }
    std::cout << "halved " << steps << " times\n";

    // do-while: the body runs at least once
    int tries = 0;
    do {
        tries++;
    } while (tries < 3);
    std::cout << "tries = " << tries << '\n';

    // range-based for visits every element of a container
    std::vector<int> values{1, 3, 5, 7};
    int sum = 0;
    for (int value : values) {
        sum += value;
    }
    std::cout << "sum = " << sum << '\n';
}