The final cout is not displaying the cin fullName:
int main()
{
string fullName;
cout << "Type your full name: ";
cin >> fullName;
cout << "Your name is: " << fullName; //this final cout is not displaying the cin fullName
system("pause>0");
}
cin does not work with spaces in the input, the rest of your input is in the buffer.
Try using getline like this:
int main()
{
string fullName;
cout << "Type your full name:" ;
getline(cin,fullName);
cout << "Your name is: " << fullName;
system("pause>0");
}
This way it will save into your variable everything until it hits a \n.
Related
The user is prompted to "enter a middle initial". What happens if they enter a space, full name, or maybe a letter followed by a period '.' ?
How can we modify the program to handle this using cin.ignore?
This is the code I currently have:
I commented out the area I'm having trouble with.
#include <iostream>
#include <string>
using namespace std;
int main ()
{
string fname, lname;
char MI;
cout << "Please enter your first name: ";
cin >> fname;
cout << "Please enter your middle initial: ";
cin.ignore(1, '\n');
cin.get(MI);
cout << "Please enter your last name: ";
//cin.ignore('\n')
cin >> lname;
cout << "Your name is " << fname << " " << MI << " " << lname << endl;
return 0;
}
When I have this other cin.ignore in it still doesn't do anything and the last name reads the extra inputs. I've tried adding a number of characters to read and it still doesn't fix the problem. When I run it it just skips the input for last name. I also tried changing the last name input to getline but if still didn't do anything.
You can just use std::getline and std::istringstream:
#include <iostream>
#include <string>
#include <sstream>
int main()
{
std::string fname, lname;
std::string MI;
std::cout << "Please enter your first name: ";
std::getline(std::cin, fname);
std::istringstream iss(fname);
iss >> fname;
do
{
std::cout << "Please enter your middle initial: ";
std::getline(std::cin, MI);
} while (MI.size() != 1);
std::cout << "Please enter your last name: ";
std::cin >> lname;
std::cout << "Your name is " << fname << " " << MI << " " << lname << std::endl;
return 0;
}
Here for fname I have used std::getline to get user input and then I've used std::istringstream to get only one word of the input.
For MI I have made it a string and until and unless the user doesn't provide a single character, the program doesn't continue.
And the lname part is the same.
You should change:
cin.ignore(1, '\n');
cin.get(MI);
To simply:
cin >> MI;
Let operator>> ignore any white space, including line breaks, between the first name and the middle initial.
After reading MI, you can then use the following to ignore everything up to the next input:
cin.ignore(numeric_limits<streamsize>::max(), '\n');
Try this:
#include <iostream>
#include <string>
#include <limits>
using namespace std;
int main ()
{
string fname, lname;
char MI;
cout << "Please enter your first name: ";
cin >> fname;
cout << "Please enter your middle initial: ";
cin >> MI;
cin.ignore(numeric_limits<streamsize>::max(), '\n');
cout << "Please enter your last name: ";
cin >> lname;
cout << "Your name is " << fname << " " << MI << " " << lname << endl;
return 0;
}
every word of txt file starts on new line
ex:
first name
last name
first part of phone number
second part of phone number
first part of address
etc..
it should look like:
name
phone number
address
city, state zip
int main()
{
string username, streetAddress, city, state, phoneNum, zip;
ofstream outputFile;
outputFile.open("list.txt");
cout << "Enter your name: ";
getline(cin, username);
outputFile << username << endl;
cout << "Enter your phone number: ";
getline(cin, phoneNum);
outputFile << phoneNum << endl;
cout << "Enter street address: ";
getline(cin, streetAddress);
outputFile << streetAddress << endl;
cout << "Enter your city: ";
getline(cin, city);
outputFile << city << ", ";
cout << "Enter your state: ";
getline(cin, state);
outputFile << state << ", ";
cout << "Enter your zip code: ";
getline(cin, zip);
outputFile << zip;
outputFile.close();
ifstream inputFile;
string list;
inputFile.open("list.txt");
while (inputFile >> list) {
cout << list << endl;
}
inputFile.close();
return 0;
}
Use getline not >>
while (getline(inputFile, list)) {
cout << list << endl;
}
Your version reads a word at a time, and then outputs each word on a separate line.
I'm trying to create a program that read and print students' data with c++. for that, I've created a struct Student, a function to read data from the user and assign it to a struct instance s1 and a function to print students' data on the screen, and I think the problem is with the function that read/write data.
Here is the my code:
#include<iostream>
#include<string>
using namespace std;
struct Student
{
char name[30];
int age;
double gpa;
string department;
};
Student read_data(Student x)
{
cout << "Name (30 characters maximum): ";
cin.get(x.name, 30);
cout << "Age: ";
cin >> x.age;
cout << "Department: ";
cin >> x.department;
cout << "GPA: ";
cin >> x.gpa;
return x;
}
void print_data(Student x)
{
cout <<
"\n***************************************************************" << endl;
cout << "Name: " << x.name << endl;
cout << "Age: " << x.age << endl;
cout << "Department: " << x.department << endl;
cout << "GPA: " << x.gpa << endl;
}
int main()
{
Student s1, s2, s3;
cout << "This program stores -Temporarily- data of three students\n" << endl;
cout << "Enter 1st student's data" << endl;
read_data(s1);
print_data(read_data(s1));
system("pause");
return 0;
}
The output of this code is:
This program stores data of three students
Enter 1st student's data
Name (30 characters maximum): Ahmed Maysara
Age: 22
Department: CS
GPA: 3.5
Name (30 characters maximum): Age: Department: GPA:
***************************************************************
Name:
Age: -858993460
Department:
GPA: -9.25596e+61
Press any key to continue . . .
As you see, the output is out of my expectations :) ..
Any help ?!
Both CinCout and David are correct.
There are a couple of problems with your code as it now stands.
The first problem is that while you successfully call the function read_data(s1), s1 is a just a copy. So, when the function sets all of the values for the student using cin, it is really just setting a copy's values. You can either make it so that you are passing in the original, or you can return the student (which you are doing) and set s1 equal to the result (which you are not).
To make sure that you pass in the original, you can go to where you declared read_data. Instead of saying Student read_data(Student x), you should place an ampersand after the parameter that you don't want to copy Student read_data(Student &x). This is called passing by reference (you reference the original instead of referencing by copy)
Alternatively, you could con just set s1 to the result where you call it in main. You could say s1 = read_data(s1); and that would work fine, though a bit more inefficiently.
Lastly, the other glaring error in the code is that you accidentally call read_data again when you say print_data(read_data(s1)). Instead, say print_data(s1).
Instead of passing and returning the structure object each time on call of read_data and print_data we could add those inside the structure itself, We could create object of Student and call the functions read and print within the same.
struct Student
{
char name[30];
int age;
double gpa;
string department;
Student(): age(0), gpa(0)
{
memset( name, 0, 30 );
}
void read()
{
cout << "\nName (30 characters maximum): ";
cin.get(name, 30);
cout << "\nAge: ";
cin >> age;
cout << "\nDepartment: ";
cin >> department;
cout << "\nGPA: ";
cin >> gpa;
}
void print()
{
cout << "\n***************************************************************" << endl;
cout << "Name: " << name << endl;
cout << "Age: " << age << endl;
cout << "Department: " << department << endl;
cout << "GPA: " << gpa << endl;
}
};
int main()
{
Student s1;
s1.read();
s1.print();
return 0;
}
You are passing copy of s1 into the read_data function, but not bothering to update the value based on the return arg. i.e. something like this should work.
s1 = read_data(s1);
print_data(s1);
Alternatively, pass by reference instead of value:
void read_data(Student& x)
{
cout << "Name (29 characters maximum): "; // requires null terminator
cin >> x.name; // just read into the buffer directly
cout << "Age: ";
cin >> x.age;
cout << "Department: ";
cin >> x.department;
cout << "GPA: ";
cin >> x.gpa;
}
And then later:
read_data(s1);
print_data(s1);
change you read_data with something like this
void read_data(Student& x)
{
cout << "Name (30 characters maximum): ";
///cin.get(x.name, 30);
cin.getline(x.name, 30);
cout << "Age: ";
cin >> x.age;
cin.ignore();
cout << "Department: ";
std::getline(cin, x.department);
///cin >> x.department;
cout << "GPA: ";
cin >> x.gpa;
cin.ignore();
// return x; can't return a value from a void function
}
and in main function or where you are calling the read_data function use
Student s1, s2, s3;
cout << "This program stores -Temporarily- data of three students\n" << endl;
cout << "Enter 1st student's data" << endl;
read_data(s1);
read_data(s2);
read_data(s3);
the reason you are getting weird values in return is that you capture buffer with cin >> instead getline
see
description of getline function
description of cin.ignore function
This question already has answers here:
Using getline(cin, s) after cin [duplicate]
(13 answers)
Closed 5 years ago.
#include<iostream>
#include<string>
#include<cstring>
using namespace std;
void cpp_string();
void cstyle_string();
int main()
{
cpp_string();
cstyle_string();
system("pause");
return 0;
}
void cpp_string()
{
string fName, lName;
char grade;
int age;
cout << "What is your first name?";
getline(cin, fName);
cout << "What is your last name?";
getline(cin, lName);
cout << "What letter grade do you deserve?";
cin >> grade;
cout << "What is your age?";
cin >> age;
cout << "Name: " << fName << ", " << lName << endl;
cout << "Grade: " << grade << endl;
cout << "Age: " << age << endl;
return;
}
void cstyle_string()
{
char fNm[20], lNm[20];
char grade;
int age;
cout << "What is your first name?";
cin.get(fNm, 20).get();
cin.clear();
cout << "What is your last name?";
cin.get(lNm, 20).get();
cout << "What letter grade do you deserve?";
cin >> grade;
cout << "What is your age?";
cin >> age;
cout << "Name: " << fNm << ", " << lNm << endl;
cout << "Grade: " << grade << endl;
cout << "Age: " << age << endl;
return;
}
I'm getting output as
What is your first name?demiurge conon
What is your last name?no
What letter grade do you deserve?a
What is your age?22
Name: demiurge conon, no
Grade: a
Age: 22
What is your first name?What is your last name?What letter grade do you deserve?What is your age?Name: ,
Grade: ╠
Age: -858993460
Press any key to continue . . .
but if I run cstyle_string() in different file then I'm not getting any errors code works perfectly.
I want to know why this is happening?
There are two question.
Redundant \n
the state of cin
The last cin in cpp_string is cin >> age.
It will leave a \n not extracted.
In first of cstyle_string is cin.get(fNm, 20).get();
The delimiting character is not extracted from the input sequence if found, and remains there as the next character to be extracted from the stream
the cin.get(FNm, 20) will parse empty input before \n, and no characters are available in the stream in actually. In this case, the failbit flag will be set and next all cin >> operator will fail.
You can only call cstyle_string and press enter directly, the same thing will happen.
It could not work if I type the Name with the space such as Peter Stroll. How to use cin.ignore() in this case?
Thank you in advance.
int main()
{
ofstream File("player.txt");
cout << "Enter player ID, Name, and Money:" << endl;
cout << "Press Ctrl + Z to quit \n" << endl;
int id;
string name;
int age;
while(cin >> id >> name >> age)
{
File << id << " " << name << " " << age << endl;
}
return 0;
}
cin won't accept any more character if it encounters tab or space key.
use getline instead
char name[64] = {0};
cin.getline(name, 64);