C++ Concepts: Exception Handling to Friend Functions

Exception Handling

#include <iostream>
#include <stdexcept>
using namespace std;
int main() {
    try {
        int numerator = 10;
        int denominator = 0;
        int res;
        if (denominator == 0) {
            throw runtime_error("Division by zero not allowed!");
        }
        res = numerator / denominator;
        cout << "Result after division: " << res << endl;
    }
    catch (const exception& e) {
        cout << "Exception " << e.what() << endl;
    }
    return 0;
}

Operator Overloading

#include <iostream>
using namespace std;
class Test {
private:
    int num;
public:
    Test(): num(8){}
    void operator ++() {
        num = num + 2;
    }
    void Print() {
        cout << "The Count is: " << num;
    }
};
int main() {
    Test tt;
    ++tt; 
    tt.Print();
    return 0;
}

Output:

The Count is: 10

Function Overloading

#include <iostream>
using namespace std;
class Cal {
public:
    static int add(int a, int b) {
        return a + b;
    }
    static int add(int a, int b, int c) {
        return a + b + c;
    }
};
int main(void) {
    Cal C;
    cout << C.add(10, 20) << endl;
    cout << C.add(12, 20, 23);
    return 0;
}

Output:

30
55

Constructor

#include <bits/stdc++.h>
using namespace std;
class Employee {
public:
    int age;
    Employee() {
        age = 50;
    }
};
int main() {
    Employee e1;
    cout << e1.age;
    return 0;
}

Destructor

#include <iostream>
using namespace std;
class Employee {
public:
    Employee() {
        cout << "Constructor Invoked" << endl;
    }
    ~Employee() {
        cout << "Destructor Invoked" << endl;
    }
};
int main(void) {
    Employee e1;
    Employee e2;
    return 0;
}

Multiply Two Numbers

#include <iostream>
int main() {
    int num1 = 5;
    int num2 = 7;
    int product = num1 * num2;
    std::cout << "The product of " << num1 << " and " << num2 << " is: " << product << std::endl;
    return 0;
}

Inline Function

#include <iostream>
inline int square(int x) {
    return x * x;
}
int main() {
    int num = 5;
    int result = square(num);
    std::cout << "The square of " << num << " is: " << result << std::endl;
    return 0;
}

Friend Function

#include <iostream>
class MyClass;
void showValue(const MyClass&);
class MyClass {
private:
    int value;
public:
    MyClass(int v) : value(v) {}
    friend void showValue(const MyClass&);
};
void showValue(const MyClass& obj) {
    std::cout << "The value of MyClass is: " << obj.value << std::endl;
}
int main() {
    MyClass obj(42);
    showValue(obj);
    return 0;
}