Question

In C++ Please

The given program reads a list of single-word first names and ages (ending with -1), and outputs that list with the age incremented. The program fails and throws an exception if the second input on a line is a string rather than an int. At FIXME in the code, add a try/catch statement to catch ios_base:: failure, and output o for the age. Ex: If the input is: Lee 18 Lua 21 Mary Beth 19 Stu 33 -1 then the output is: Lee 19 Lua 22 Mary 0 Stu 34

Answer 1

Solution - The required modified code in C++ is given below -

#include <bits/stdc++.h> using namespace std; int main(int argc, char* argv[]){    string inputName;    int age;    bool flag = true;    //set exception mask for cin stream    cin.exceptions(ios::failbit);    cin>>inputName;    while(inputName != "-1"){        //using try and catch handling the exception for second input as string        //and setting the age to -1            try{                    cin >> age;                    flag = true;            }            catch(std::ios_base::failure &fail) {                    flag = false;                    cin.clear();                    std::string tmp;                    getline(cin, tmp);               age = -1;            }        cout<<inputName<<" "<<(age+1)<<endl;        cin>>inputName;    }    return 0; }

Explanation -

1. In this code i inserted try/catch to catch the exception of string instead of int.
2. Cleared cin's failbit and put cin in usable state using cin.clear().
3. In catch, age is set to -1, so the final output will be age = 0 for this exception.
4. The rest of the code is same. I have added only the required part.

Refer to the screenshot below for code and output -

#include <bits/stdC++.h> using namespace std; int main(int argc, char* argv[]) { string inputName; int age; bool flag = true; //set exception mask for cin stream cin.exceptions(ios:: failbit); cin>>inputName; while(inputName != "-1"){ //using try and catch handling the exception for second input as string 1/and setting the age to - 1 try { cin >> age; flag = true; } catch(std::ios_base:: failure &fail) { flag = false; cin.clear(); std::string tmp; getline(cin, tmp); age = -1; } cout<<inputName<<" "<<(age+1)<<endl; cin>>inputName; } return 0; } //Below is the output O namrta@namrta: - namrta@namrta: $ g++ code1.cpp namrta@namrta: $ ./a.out Lee 18 Lee 19 Lua 21 Lua 22 Mary Beth 19 Магу 0 Stu 33 Stu 34 -1 namrta@namrta:-$