JuniorTheoryCommon

What does the program print?

C++

#include <iostream>

int add(int x) {
    static int total = 0;
    total = total + x;
    return total;
}

int main() {
    int total = add(5);
    std::cout << add(2) << ' ' << total << '\n';
}

7 5

Expecting 2 5: a static local is initialized once, not on every call, so the second call adds 2 to the 5 it kept.
Expecting 7 7: static changes how long total in add lives, not where it is visible, so total in main is a separate variable.

How would the output change if total in add were declared without static?
Is it safe to call a function with a static local from several threads at once?

Back to questions Open topic in roadmap →Answer it yourself — Quiz

Back to questions

JuniorTheoryCommon

What does the program print?

C++

#include <iostream>

int add(int x) {
    static int total = 0;
    total = total + x;
    return total;
}

int main() {
    int total = add(5);
    std::cout << add(2) << ' ' << total << '\n';
}

7 5

Expecting 2 5: a static local is initialized once, not on every call, so the second call adds 2 to the 5 it kept.
Expecting 7 7: static changes how long total in add lives, not where it is visible, so total in main is a separate variable.

How would the output change if total in add were declared without static?
Is it safe to call a function with a static local from several threads at once?

Back to questions Open topic in roadmap →Answer it yourself — Quiz