How can I use IF statements with string user inputs?

Question

I'm a c++ newbie and have spent half a day googling this. Most posts seem vague or complex. And I have a feeling that there's a simpler way to do this. Any help is appreciated. A simple program that calculates tax based on the state entered by user:

#include <iostream>

int main()
{
    std::cout << "Enter your order amount: ";
    int amount{};
    std::cin >> amount;

    std::cout << "Which state do you reside in? ";
    std::string state{};
    std::cin >> state;

    if (state == "WI") //THIS IS SIMILAR TO HOW I WOULD DO IT IN PYTHON | C++ doesn't work this way
        std::cout << "Your tax is 5.0$" << std::endl;
        std::cout << "Your total is " << amount + 5.0;

    else
        std::cout << "Your tax is 0.0$" << std::endl;
        std::cout << "Your total is " << amount;

    return 0;
}

Your code is pretty nice for a newby. A lot of info can be found on en.cppreference.com/w/cpp/string/basic_string — JHBonarius
– JHBonarius, Commented Nov 3, 2019 at 21:48
yes c++ works this way. You can compare a std::string to another string with the operator == . You however need parentheses around all the things that are in the if statement. In C++ you need to use {} instead of indentation to indicate scope. — Wolfgang Brehm
– Wolfgang Brehm, Commented Nov 3, 2019 at 21:48
This has nothing to do with strings, but with proper C++ grammar. C++ is not Python, and indentation is utterly meaningless in C++. You need to use braces. See your C++ book for more information. — Sam Varshavchik
– Sam Varshavchik, Commented Nov 3, 2019 at 21:50
@constraintAutomaton welcome to modern C++... en.cppreference.com/w/cpp/language/initialization — JHBonarius
– JHBonarius, Commented Nov 3, 2019 at 21:51
@Omnifarious thank you for clarifying that. I was aware that C++ didn't have any rules on indentation. I simply carried over the indentation style from python to make it readable, as you said. — Praveen Gunasekaran
– Praveen Gunasekaran, Commented Nov 3, 2019 at 23:57

Richard Critten · Accepted Answer · 2019-11-03 22:03:18Z

4

Note the addition of { and } to group the statements after the if and else

#include <iostream>

int main()
{
    std::cout << "Enter your order amount: ";
    int amount{};
    std::cin >> amount;

    std::cout << "Which state do you reside in? ";
    std::string state{};
    std::cin >> state;

    if (state == "WI")
    {
        std::cout << "Your tax is 5.0$" << std::endl;
        std::cout << "Your total is " << amount + 5.0;
    }
    else
    {
        std::cout << "Your tax is 0.0$" << std::endl;
        std::cout << "Your total is " << amount;
    }

    return 0;
}

After an if (condition) or else the language only allows a single statement. The braces { and } enclose a sequence of statements into a Compound Statement.

For possibly clearer language see Compound statements here: https://en.cppreference.com/w/cpp/language/statements

edited Nov 3, 2019 at 22:03

answered Nov 3, 2019 at 21:56

Richard Critten

2,1453 gold badges15 silver badges19 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Adrian Mole Over a year ago

Maybe an explanation of the "compound statement" would be good here?

Collectives™ on Stack Overflow

How can I use IF statements with string user inputs?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related