Handling Errors in C++ (Exceptions)

try: A block where code is run and if an error occurs an exception is thrown, potentially to catch with other code throw: raises an exception (when something bad happens, someone should handle the problem!!!!!) catch: a block where an exception is caught and handled (in conjunction with try)

The idea is to keep a watch on particular section of code, if we get an exception raise/throw that exception. Then look for a “Catcher” that can handle that kind of exception. If a Catcher is found, the Catcher will handle the error, otherwise the program will end!!

Try Block

contains code that we want to keep an eye on, to watch if any kind of errors occur
If an error occurs anywhere in the try block, execution stops immediately in the block, and the try looks for an appropraite catch to deal with the error.

Exception Block

#include<iostream>
using std::cout; using std::cin; using std::endl;

int main() {

    // handle errors

    double num1 = 0, num2 = 0;

    cout << "Enter Number 1: ";
    cin >> num1;

    cout << "Enter Number 2: ";
    cin >> num2;

    try{

        if(num2 == 0){
            throw "Divison by zero is not possible";
        }
        else{
            cout << "yes it will work" << endl;
            cout << "answer is: " << num1 / num2 << endl;       
        }
    }
    catch(const char exp)
    {
        cout << "Error: " << exp << "\n";
    }
}

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more code

#include<iostream>
using std::cout; using std::cin; using std::endl; using std::exception;


int main() {

    try {

        int age = 15;
        if (age >= 18) {
            cout << "Access granted - you're old enough! " << endl;
        }
        else{

            throw (age);
        }

    }
    catch (int myNum)
    {
        cout << "Access Denied, you must be at least 18 years old " << endl;

        cout << "your age is: " << myNum << endl;
    }


}

Handling Multiple “Catches

#include<string>
using std::string;

#include<iostream>
using std::cout; using std::cin; using std::endl; using std::exception;


int main() {

    try {

        string name;

        name = "Devin";

        int age = 18;
    
        if (age >= 18) {
            cout << "Access granted - you're old enough! " << endl;
        }
        else{

            throw (age);
        }

        if (name == "Austin")
        {
            cout << "Hi Austin!!" << endl;
        }
        else{

            throw (name); // should send it to the correct catch 
        }


    }
    catch (int myNum)
    {
        cout << "Access Denied, you must be at least 18 years old " << endl;

        cout << "your age is: " << myNum << endl;
    }

    catch (string name_wrong)

    {
        cout << "The name is wrong! " << endl;
    }


}

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