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1. True or false: this function is pure. ``

cpp
int offset = 2;
int shifted(int x) { return x + offset; }

``

True, because the result depends only on xFalse, because the result depends on the global offset, which can change between calls

2. True or false: this function is pure. ``

cpp
int next_ticket_pure(int counter) { return counter + 1; }

``

True, because the same argument always gives the same result and nothing outside the function changesFalse, because the result depends on how many times the function has been called

3. What does this program print? ``

cpp
#include <iostream>

int offset = 2;
int shifted(int x) { return x + offset; }

int main() {
    std::cout << shifted(5) << ' ';
    offset = 4;
    std::cout << shifted(5) << ' ' << shifted(5) << '\n';
}

``

5 5 55 9 97 9 97 7 9

4. What does this program print? ``

cpp
#include <iostream>

int next_ticket() {
    static int counter = 0;
    return ++counter;
}

int next_ticket_pure(int counter) { return counter + 1; }

int main() {
    std::cout << next_ticket() << ' ' << next_ticket() << ' ' << next_ticket() << '\n';
    std::cout << next_ticket_pure(7) << ' ' << next_ticket_pure(7) << '\n';
}

``

3 3 3 then 8 81 2 3 then 7 70 1 2 then 8 81 2 3 then 8 8

5. Which of these is hidden state, meaning an input the function uses that is not in its parameter list?

The parameter priceA global variable tax_rate read inside the function bodyThe return value of the functionThe literal argument 200 in a call

Pure functions