c++ programing 

 

1) Given the code fragment below, what does it print when the user enters 2 and then 3?

Could you explain why the result is not 5?

    // 0 to 9

    char digit1, digit2;

    cout<<"Enter a digit: ";

    cin>> digit1;

    cout<<"Enter another digit: ";

    cin>> digit2;

    cout<<"Sum of "<<digit1<<" + "<<digit2<<" is "<<(digit1 + digit2)<<endl;

 

2) Same as the question above but the code has been modified slightly. What is the output now when the user enters 2 and then 3?

    // 0 to 9

    string digit1, digit2;

    cout<<"Enter a digit: ";

    cin>> digit1;

    cout<<"Enter another digit: ";

    cin>> digit2;

    cout<<"Sum of "<<digit1<<" + "<<digit2<<" is "<<(digit1 + digit2)<<endl;

 

3) Same as the question above but the code has been modified slightly. What is the output now when the user enters 2 and then 3?

    // 0 to 9

    int digit1, digit2;

    cout<<"Enter a digit: ";

    cin>> digit1;

    cout<<"Enter another digit: ";

    cin>> digit2;

    cout<<"Sum of "<<digit1<<" + "<<digit2<<" is "<<(digit1 + digit2)<<endl;

 

4) From the examples above, when a user types a value like 2 or 3 as input, is that value a number, a character, or a string?

What determines what the program will treat the value as?

 

5) Same as question 3 but the user now enters "two" when asked for the first digit. What does the program print?

    // 0 to 9

    int digit1, digit2;

    cout<<"Enter a digit: ";

    cin>> digit1;

    cout<<"Enter another digit: ";

    cin>> digit2;

    cout<<"Sum of "<<digit1<<" + "<<digit2<<" is "<<(digit1 + digit2)<<endl;

 

6) Same as question 1 but the user now enters "two" when asked for the first digit. What does the program print?

    // 0 to 9

    char digit1, digit2;

    cout<<"Enter a digit: ";

    cin>> digit1;

    cout<<"Enter another digit: ";

    cin>> digit2;

    cout<<"Sum of "<<digit1<<" + "<<digit2<<" is "<<(digit1 + digit2)<<endl;

 

7) Given the code fragment below, what does it print when the user enters John Smith? Please briefly explain why this happens.

    string name;

    cout<<"Enter name: ";

    cin>> name;

    cout<<"Hello "<<name<<endl;

 

8) Please briefly explain (~3 lines) how reading from a file is similar to reading from cin and writing to a file is similar to writing to cout.

 

9) Give an example (~2 lines) of when you may want to read a file character by character as opposed to word by word. Give an example (~2 lines) when it would be more appropriate to read the file word by word.

 

10) Give a code fragment that attempts to open a file "myFile.txt" and terminates the program if the file was not opened successfully.