Reusable Function

[menewbie]

Hi Friends!

I have completed my project just can not find a way to reduce my code, especially i could not made a function seperately to open file and reuse the code. And particularly I am repeating my code to open the text file because I do not know how to make a function for it and call it repeatedly.

myFile("fileName", ios::in);

Is it possible to make a separate function and call it from different places?

#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;

int menu(int);
int myChoice(char, int);

int main(){
    int loopCondition = 1;

    cout << "\n\nTemperature Statistics\n----------------------\n\nReading logged values for processing and presentation...\n\nPress Enter for menu: ";
    cin.get();
    menu(loopCondition);
    return 0;
}


int menu(int loopCondition){
    char choice;
    while(loopCondition){
        cout<<"\n\nMENU\n----\n\n1. Display temperature values\n2. View maximum and minimum temperatures\n3. View average temperature\n4. Quit\n\nMake your choice: ";
        cin.get(choice);
        cin.get();
        loopCondition = myChoice(choice, loopCondition);
        cout<<"\n\nPress Enter to continue:";
        cin.get();
    };
    return 0;
}

int myChoice(char choice, int loopCondition){
    double fileToken;
    int i;
    if(choice=='1'){
        cout<<"\nDisplaying the latest 24 temperature values:\n\n";
        ifstream myFile("templog.txt",ios::in);
        for(i=0;i<24;i++){
            if(i%6==0)
            cout<<endl;
            myFile>>fileToken;
            cout<<fixed<<setprecision(2)<<setw(8)<<fileToken;
        }
    }
    else if(choice=='2'){
        cout<<"\nCalculating the maximum and minimum temperature...\n";
        double max=0, min=0;
        ifstream myFile("templog.txt",ios::in);
        myFile>>fileToken;
        max=min=fileToken;
        for(int i=1;i<24;i++){
            myFile>>fileToken;
            if(fileToken>max)
            max=fileToken;
            if(fileToken<min)
            min=fileToken;
        }
        cout<<"\nMaximum temperature: "<<fixed<<setprecision(2)<<max<<" degrees Celcius\n";
        cout<<"\nMinimum temperature: "<<min<<" degrees Celcius\n";
    }
    else if(choice=='3'){
        cout<<"\nCalculating average temperature...\n";
        double total=0.0, average=0.0;
        ifstream myFile("templog.txt");
        for(i=0;i<24;i++){
            myFile>>fileToken;
            total+=fileToken;
        }

        average=total/24;
        cout<<"\nAverage temperature: ";
        cout<<fixed<<setprecision(2)<<average<<" degrees Celcius\n";
    }
    else if(choice=='4'){
        loopCondition = 0;
        cout << "\n\nTerminating the program.";
        return (0);
    }
}

Thank you very much

Sincere Regards,

[IWishIKnew]

in myChoice, you need to add a return at the end.

You also need to close the file streams when you're done with them. That could become a serious problem if you don't correct it.

You can eliminate about half of what you wrote for myChoice by writing a function that just gets the last X temps and returning them. The calculations can be done by the caller.

[menewbie]

Hi !

I have fixed all the error and requirement but it is not properly handling file opening and reading...

I will appreciate if someone helps me out

here is my code

#include <iostream>
#include <fstream>
#include <iomanip>
//using namespace std; // full namespace is not used any more

int menu();
int myChoice(char);
char inputValidating();

int main(){
	std::cout << "\n\nTemperature Statistics\n----------------------\n\nReading logged values for processing and presentation...\n\nPress Enter for menu: ";
    std::cin.get();
    menu();
    return 0;
}

int menu(){
    char choice;
    int loopCondition = 1;
	while(loopCondition){ 
		system("cls");
		std::cout<<"\n\nMENU\n----\n\n1. Display temperature values\n2. View maximum and minimum temperatures\n3. View average temperature\n4. Quit\n\nMake your choice: ";
		choice = inputValidating(); // validating the user input
		std::cin.get();
		loopCondition = myChoice(choice); 
		std::cout<<"\n\nPress Enter to continue:";
		std::cin.get();
    };
    return 0;
}

//Error Handling for user interaction
char inputValidating(){
	char choice;
	bool valid = false;
		while(!valid){
			valid = true;
			std::cin>> choice;
			if(std::cin.fail()){
				std::cin.clear();
				std::cin.ignore();
				std::cout<<"incorrect input";
				valid = false;
			}
		}
		return choice;
}

int myChoice(char choice){
    double fileToken;
	std::string fileName = "templog.txt"; // Use of Constant
	std::ifstream myFile(fileName.c_str(),std::ios::in); //text file is only opened once
	int i, loopCondition=1;
    if(choice=='1'){
		std::cout<<"\nDisplaying the latest 24 temperature values:\n\n";
		if(myFile.is_open()){ // Error handling for file opening and reading
			for(i=0;i<24;i++){
				if(i%6==0)
				std::cout<<std::endl;
				myFile>>fileToken;
				std::cout<<std::fixed<<std::setprecision(2)<<std::setw(8)<<fileToken;
			}
		}else{
			std::cout<<"Error occured while opening file";
			return 0;
		}	
    }
    else if(choice=='2'){
		std::cout<<"\nCalculating the maximum and minimum temperature...\n";
		double max=0, min=0;
        myFile>>fileToken;
        max=min=fileToken;
        for(i=1;i<24;i++){
            myFile>>fileToken;
            if(fileToken>max)
            max=fileToken;
            if(fileToken<min)
            min=fileToken;
        }
		std::cout<<"\nMaximum temperature: "<<std::fixed<<std::setprecision(2)<<max<<" degrees Celcius\n";
		std::cout<<"\nMinimum temperature: "<<min<<" degrees Celcius\n";
    }
    else if(choice=='3'){
		double total=0.0, average=0.0;
		std::cout<<"\nCalculating average temperature...\n";
        for(i=0;i<24;i++){
            myFile>>fileToken;
            total+=fileToken;
        }
		average=total/24;
		std::cout<<"\nAverage temperature: ";
		std::cout<<std::fixed<<std::setprecision(2)<<average<<" degrees Celcius\n";
	}
    else if(choice == '4'){
        std::cout << "\n\nTerminating the program.";
		myFile.close(); //Filed Closed on the Exit
        return loopCondition = 0;
    }
	else {
		std::cout << "\n\nYou have entered a wrong choice, Try again.";
	}
	myFile.close(); // File Closed after reading
	return loopCondition = 1;
}