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1. What is the bug in this code? ``

cpp
void check(int age, bool has_ticket) {
    if (age >= 18)
        if (has_ticket)
            cout << "Entry allowed" << endl;
    else
        cout << "Entry refused" << endl;
}

``

The age check should use > instead of >=The cout line is missing a semicolonThe else pairs with if (has_ticket), so a person under 18 gets no refusal messageThe function should return a bool instead of void

2. What is the bug in this function? ``

cpp
bool is_long(const string* text) {
    return text->size() > 5 && text != nullptr;
}

``

The function should return true for an empty stringThe null check is on the right of &&, so size() runs on a null pointer firstThe comparison should use == instead of >The const should be removed from the parameter

3. What is the bug in this loop? ``

cpp
while (node->value < limit && node != nullptr) {
    ++count;
    node = node->next;
}

``

node->value is read before node != nullptr is checked, so after the last node it reads through nullptrThe loop never increments countlimit should be passed by referenceThe loop should test node->next instead of node

4. What does this program print? ``

cpp
#include <iostream>
using namespace std;

void run(int a, int b, int c) {
    if (a == 1)
        if (b == 1)
            if (c == 1)
                cout << "A";
            else
                cout << "B";
        else
            cout << "C";
    cout << endl;
}

int main() {
    run(1, 0, 1);
}

``

ABnothingC

5. What does this program print? ``

cpp
#include <iostream>
#include <string>
using namespace std;

bool is_blank(const string* text) {
    return text == nullptr || text->empty();
}

int main() {
    string a = "";
    string b = "x";
    cout << boolalpha;
    cout << is_blank(nullptr) << " " << is_blank(&a) << " " << is_blank(&b) << endl;
}

``

true true falsefalse true falsetrue false falsefalse false true

Dangling else and nulls