Get enum key from unordered map by string value

Question

I need a function that needs to check if the input (std::string) is unique and return it's corresponding enum value.

I already have been able to implement this function with just a simple vector, which checks if the input is unique.

std::string checkIfInputUnique(std::string inputString, std::vector<std::string> commands)
{
    std::transform(inputString.begin(), inputString.end(),inputString.begin(), ::toupper);
    std::string uniqueCommand = "";
    std::string commandInVector = "";
    bool uniqueCommandFlag = true;
    for(std::string command: commands){
        int i = 0;
        int length = inputString.length();
        std::string tempUniqueCommand = "";
        while(i != length){
            if(inputString.at(i) != command.at(i)){
                break;
            }
            tempUniqueCommand.push_back(inputString.at(i));
            i++;

            if(command.length() < inputString.length()){
                break;
            }
        }
        if(tempUniqueCommand.length() > uniqueCommand.length()){
            uniqueCommandFlag = true;
            uniqueCommand = tempUniqueCommand;
            commandInVector = command;
        }
        else if (tempUniqueCommand.length() == uniqueCommand.length()){
            uniqueCommandFlag = false;
        }
    }
    if(uniqueCommand.length() == 0){
        return "NOT FOUND";
    }
    else if(uniqueCommandFlag == false){
        return "NOT UNIQUE";
    }
    else{
        return commandInVector;
    }
}

For example: if my inputString = "HEL" and my vector containst{"HELLO", "WORLD"}, it returns "HELLO".

However, instead of a vector, I now have a map of an enum (key) and a string (value), and when the string in the map is unique, it should return it's key.

enumE checkifInputUniqueMap(std::string inputString, std::unordered_map<enumE, std::string> commands){};

For example if my inputString = "HEL" and my map = {{enumE::HELLO, "HELLO"},{enumE::WORLD, "WORLD"}} and enum class enumE{ HELLO,WORLD, NOTUNIQUE, NOTFOUND

};, it should return enumE::HELLO.

I tried to adapt the code above for the vector to suit this function, but I am not really getting anywhere.

Answer 1

Based on the description of your example, here is a quick implementation . Of course, the logic may not be entirely what you wrote, but I am sure you can tweak it.

• Why would you iterate through the whole string if std::string has a std::string::find function which will find a substring for you?
• Is it necessary to go through all the trouble you wrote above? Does the code need to be that dense and unreadable?

Feel free to play around with that function and implement your logic.