I'm trying to assign some values to a vector from cin.
How can I achieve that the while loop breaks immediately after a specific word, e.g. end, was entered?
In my example it only breaks if I enter this word as "age", so only at the end of the loop. If I enter it at the beginning (as "name") it just continues.
#include <iostream>
#include <vector>
using namespace std;
struct person {
string name;
string age;
};
int main() {
vector<person> myPerson;
string text;
while(text != "end") {
person tempPerson;
cout << "Name:" << endl;
cin >> text;
tempPerson.name = text;
cout << "Age:" << endl;
cin >> text;
tempPerson.age = text;
myPerson.push_back(tempPerson);
}
for(int i=0; i<myPerson.size(); i++) {
cout << "Person No. " << i << ": " << endl;
cout << "Name: " << myPerson[i].name << endl;
cout << "Age: " << myPerson[i].age << endl;
}
return 0;
}
break out of the loop if "end" is entered.
while (true) {
cin >> text;
if (text == "end")
break;
// ...
}
Related
using namespace std;
int main()
{
char repeat;
do
{
string str;
cout << "What is your first and last name? " << endl;
getline(cin, str);
string findSpace = " ";
int found = str.find(findSpace) + 1;
cout << str[0] << str[found] << endl;
cout << "repeat? " << endl;
cin >> repeat;
} while (repeat == 'y');
}
I have this code that helps me get the initials of the first and last name. But when I go to repeat the code it automatically couts "What is your first and last name?" as well as "repeat?". It won't go through the steps of asking for the first and last name, giving the initials, and then asking if the user wants to repeat.
What am I doing wrong here?
using namespace std;
int main()
{
char repeat;
do
{
string str;
cout << "What is your first and last name? " << endl;
//
getline(cin >> ws, str);
string findSpace = " ";
int found = str.find(findSpace) + 1;
cout << str[0] << str[found] << endl;
cout << "repeat? " << endl;
cin >> repeat;
} while (repeat == 'y');
}
Thanks to the comment by mch I've solved it. This is my solution.
#include <iostream>
#include <string>
#include <vector>
using namespace std;
//void FillNames(vector<string> & vecNames);
//void SortNames(vector<string> & vecNames);
int main() {
string firstName;
int i = 0;
cout << "Information:" << endl;
cout << "EOF character in windows is Control + Z" << endl;
cout << "and EOF character on Mac is Control + D:" << endl;
cout << "-----------------------------------------------" << endl;
while (i < 13) {
cout << "Enter first name only in all caps (example: JOHN)" << endl;
cout << "Enter EOF character to exit name entry: ";
cin >> firstName;
i++;
}
}
Here is a link to what i'm trying to accomplish.
https://drive.google.com/file/d/1AuW9hQPbd1f294dCZN6Q8Ac6lgIy0Ivf/view?usp=sharing
You can use the stream's input state to break the loop when EOF is entered:
while (i < 13) {
cout << "Enter first name only in all caps (example: JOHN)" << endl;
cout << "Enter EOF character to exit name entry: ";
if (cin >> firstName)
i++;
else
break;
}
The code has been updated in order to solve a different section of the whole picture within the coding process. Now I need help within the second case of the switch. The problem now is that the while loop always executes within the second function of the switch. I don't no if the array is verifying the number or the user input.. I could use while (string::npos != studID2[i].find_first_of(studID2[a])) I need some help here it is getting very complex and I am hitting a brick wall.
1)I need to verify each user input using a for loop and two arrays. I tried to increment the of the arrays in order to execute the while statement.
2) If the condition is true the while loop will execute telling the user that he must enter 3 different digits, the reason why I am using an array and a for loop is because the user gets to choose how many names and IDs he would like to input into the archive.
3) The for loop increments a++ in order to check to see if the last input is the same as the newest user input.
It is getting too complex here any help would be appreciated.
Number 4 is the expected error...
4) The second user input will always make the while loop run regardless of what digits you use.
5)The reason for so much code is because I am not completely sure where the problem begins and the problem ends...
6)I am using two arrays here in this problem.
7)There is another error if you change the a from 0 to 1 it will automatically close the program. The reason you would change the a to a 1 is so that a will increment by 1.
//I am trying to verify multiple inputs with a array and a for loop..
// The expected output is that the second ID you input in the second option of the switch case is going to execute the while loop.
//I am trying to execute the while loop properly within the second function of the switch case.
//I need help any form of help can be appreciated.
#include<iostream>
#include<string>
#include<fstream>
#include<sstream>
#include <cstddef>
#include <limits>
#include <cstdlib>
int name2 = 0;
int studentID = 0;
int email2 = 0;
int studentID2[100];
std::string let("abcdefghijklmnopqrstuvwxyz");
int numbers = (1, 3, 0);
std::string str;
std::string name;
std::string studID;
std::string studID2;
std::string email;
std::string emailbackup;
std::string studFinal;
std::stringstream concatenate;
std::stringstream concatenatetwo;
int x;
std::string fileName = "StudentArchive.txt";
void emailEntry();
void readDocument();
int readNumber();
void deleteInformation();
void getStudentinformation();
using std::cout;
using std::cin;
int main()
{
do {
std::cout << "What would you like to do?" << std::endl;
std::cout << "1)Would you like to see the archive?" << std::endl;
std::cout << "2)Would you like to register student information?" << std::endl;
std::cout << "3)Would you like to find a student within the registry?" << std::endl;
std::cout << "4)Delete all student information?" << std::endl;
std::cout << "5)Exit Program?" << std::endl;
std::cin >> x;
switch (x)
{
case 1:
readDocument();
break;
case 2:
emailEntry();
break;
case 3:
deleteInformation();
break;
case 4:
getStudentinformation();
break;
case 5:
cout << "Exiting Program." << std::endl;
system("PAUSE");
break;
}
} while (x != 5);
}
void emailEntry()
{
std::ofstream outfile;
outfile.open(fileName, std::ios_base::app);
int amountofStudent;
std::cout << "How many student Identities would you like to enter?" << std::endl;
std::cin >> amountofStudent;
cin.ignore();
Here is where the user chooses how many students he would like to enter into the registry. I am having difficulty verifying the user input regarding the studentIDs.
if (outfile.is_open()) {
for (int i = 0; i < amountofStudent; i++)
{
std::string studID2[100];
std::stringstream(name) >> name2;
cout << "Please enter your name.." << std::endl;
getline(cin, name);
outfile << name;
std::stringstream(name2) >> name;
while (std::string::npos != name.find_first_of("0123456789"))
{
cout << "You must have letter within user input." << std::endl;
cout << "Please enter your name." << std::endl;
getline(cin, name);
outfile << name;
}
//I need to check to see if the first 3 numbers are correct?
//The student ID must be at least 6 digits, and the first 3 numbers must be 130.
cout << "Please enter Your student I.D." << std::endl;
getline(cin, studID);
outfile << studID;
std::stringstream(studID) >> studentID;
while (/*std::string::npos != studID.find_first_of("130") */ studentID != 130 /*&& studID.length() <= 6*/)
{
std::stringstream(studentID) >> studID;
cout << "You must enter 130 as the first 3 digits" << std::endl;
getline(cin, studID);
std::stringstream(studID) >> studentID;
}
//==============
//std::stringstream(studentID2) >> studID2[i];
cout << "Please enter the second part of the student I.D. " << studentID << "-" << std::endl;
getline(cin, studID2[i]);
outfile << studID;
//outfile << studID2[i];
std::stringstream(studID2[i]) >> studentID2[i];
//cout << i;
This is the for loop, and array I need help with. Below this text is where I am having problems. I don't understand why the while loop won't execute I am trying to verify the first user input with the next user input. For example if the user enters 888 on the first input then tries to enter 888 on the second input they need to re-enter different digits or the input will go on forever. The main struggle is if the user chooses to enter multiple student accounts within this minor registry.
for (int a = 0; a < i; i++)
{
while (studID2[i] == studID2[a])
{
cout << "The numbers cannot be repeated you must re-enter the student ID." << std::endl;
std::stringstream(studentID) >> studID;
cout << "You must enter 130 as the first 3 digits" << std::endl;
getline(cin, studID);
std::stringstream(studID[i]) >> studentID;
//std::stringstream(studID2[i]) >> studentID2;
cout << "Please enter the second part of the student I.D. " << studentID << "-" << std::endl;
getline(cin, studID2[i]);
outfile << studID;
outfile << studID2[i];
//std::stringstream(studID2[i]) >> studentID2;
}
}
This is where the verification of the studentIDs end...
while (/*std::string::npos != studID.find_first_of("130") */ studID2[i].length() < 3 || studID2[i].length() > 3)
{
//stringstream(studentID) >> studID;
cout << "Add 3 more digits." << std::endl;
getline(cin, studID2[i]);
outfile << studID2[i];
}
concatenate << studentID << "-" << studID2 << std::endl;
studFinal = concatenate.str();
/*while (studID.length() != 6)
{
cout << "You must enter 130 as the first 3 digits and you must have 6 digits." << std::endl;
std::cin >> studID;
}*/
cout << "Please enter your email.." << std::endl;
std::stringstream(email) >> email2;
getline(cin, email);
outfile << email;
std::stringstream(email2) >> email;
while (email == emailbackup || email.empty())
{
cout << "Please enter your email..." << std::endl;
std::stringstream(email) >> email2;
getline(cin, email);
outfile << email;
std::stringstream(email2) >> email;
}
concatenatetwo << email << "#atlanticu.edu" << std::endl;
email = concatenatetwo.str();
emailbackup = email;
cout << "Your email is" << email << std::endl;
std::system("pause");
}
}
outfile.close();
}
Here is where the user deletes info..
void deleteInformation()
{
std::ofstream infile(fileName, std::ios::trunc);
if (infile.is_open()) {
cout << "You have now have no books." << std::endl;
system("PAUSE");
system("cls");
infile.close();
}
}
void getStudentinformation()
{
std::ifstream outfile;
outfile.open(fileName);
if(outfile.is_open())
{
int x;
cout << "1)Name" << std::endl;
cout << "2)studentNumber" << std::endl;
cout << "3)Exit" << std::endl;
cin >> x;
switch (x)
{
case 1:
cout << "Please enter the student's name.." << std::endl;
getline(cin, name);
cout << name << std::endl;
outfile >> name;
break;
case 2:
cout << "Please enter the first 3 digits of the student's ID number.. " << std::endl;
getline(cin, studID);
cout << "Please enter the last 3 digits of the student's ID number.. " << std::endl;
getline(cin, studID2);
outfile >> studID;
outfile >> studID2;
break;
case 3:
std::string choice;
cout << "Would you like to return to the main menus?" << std::endl;
cin >> choice;
break;
}
}
}
int readNumber()
{
int number;
cin >> number;
std::string tmp;
while (cin.fail())
{
cin.clear();
std::getline(cin, tmp);
cout << "Only numbers please: ";
cin >> number;
}
getline(cin, tmp);
return number;
}
Here is where the user reads the txt doc.
void readDocument()
{
std::ifstream infile;
infile.open(fileName);
if (infile.is_open()) {
std::string info;
while (getline(infile, info))
{
cout << info << std::endl;
}
infile.close();
}
else {
cout << fileName << " doesn't exists !" << std::endl;
}
std::system("PAUSE");
std::system("cls");
}
//std::ofstream outfile;
//outfile.open(fileName, ios_base::app);
//if(outfile.is_open()) {
// cout << "How many books do you want to add: ";
// int n = readNumber();
// while (n <= 0)
// {
// cout << "Only positive numbers, please: ";
// n = readNumber();
// }
// for (int i = 0; i < n; i++) {
// string title = "Book's Title: ";
// cout << title;
// title += readText();
// string author = "Author: ";
// cout << author;
// author += readText();
// string genre = "Book's Genre: ";
// cout << genre;
// genre += readText();
// cout << endl;
// outfile << title << endl;
// outfile << author << endl;
// outfile << genre << endl << endl;
// }
//}
// outfile.close();
// cout << "Books have been added to the library !" << endl;
// system("PAUSE");
// system("cls");
Think about your function signature.
void email(string emailbackup);
Do you actually want the caller to pass a string to the function email()?
Because you then define emailbackup inside the function again.
You want something like this probably...
...
case 2:
const string backup = "backup#email";
email(backup);
break;
...
void email(string emailbackup)
{
// string emailbackup; // delete this line
...
}
Also, remove using namespace std; and be consistent with your namespace usage. Why add using namespace cout, cin etc if you are calling them with the namespace explicitly i.e. std::cin, std::cout.
Either add using namespace std::cout and use cout rather than std::cout or vice versa. Don't mix it up. Same with std::string and string. Makes it look like you defined your own string...
Just one last thing, for the sake of readability I would suggest breaking this email function into smaller functions. For instance:
void email(string emailbackup)
{
...
int studentID = getStudentID();
string studentEmail = getStudentEmail();
...
}
int getStudentID()
{
int studentID;
cout << "Please enter Your student I.D." << std::endl;
std::cin >> studID;
stringstream(studID) >> studentID;
while (/*std::string::npos != studID.find_first_of("130") */ studentID != 130 /*&& studID.length() <= 6*/)
{
stringstream(studentID) >> studID;
cout << "You must enter 130 as the first 3 digits" << std::endl;
std::cin >> studID;
stringstream(studID) >> studentID;
}
return studentID;
}
After my first entry, my second entery name field fills up with the input buffer from the previous entry. Why? I am even using the getline but the problem still persists. Please help me with the problem. This is question from Jumping Into C++ book .
#include <iostream>
#include <string>
using namespace std;
struct Person
{
string name;
string address;
long long int PhoneNumber;
};
void displayEntries(Person p[])
{
int enteryNumber;
cout << "Enter the entry number of the person for details(enter 0 to display all entries): ";
cin >> enteryNumber;
if(enteryNumber == 0)
{
for(int i = 0; i < 10; i++)
{
cout << "Entery Number: " << i + 1;
cout << "Name: " << p[i].name << endl;
cout << "Address: " << p[i].address << endl;
cout << "Phone Number: " << p[i].PhoneNumber << endl;
}
}
do
{
cout << "Entery Number: " << enteryNumber;
cout << "Name: " << p[enteryNumber].name << endl;
cout << "Address: " << p[enteryNumber].address << endl;
cout << "Phone Number: " << p[enteryNumber].PhoneNumber << endl;
} while (enteryNumber != 0);
}
int main()
{
Person p[10];
for(int i = 0; i < 10; i++)
{
cout << "Enter the details of the person\n\n";
cout << "Name: ";
getline(cin, p[i].name);
cout << "Address: ";
getline(cin, p[i].address);
cout << "Phone Number: ";
cin >> p[i].PhoneNumber;
cout << endl;
}
displayEntries(p);
return 0;
}
You can see what is happening when you read the reference for getline:
When used immediately after whitespace-delimited input, e.g. after
int n;
std::cin >> n;
getline(cin, n); //if used here
getline consumes the endline character left on the input stream by operator>>, and returns immediately. A common solution is to ignore all leftover characters on the line of input with
cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
before switching to line-oriented input.
cin >> p[i].PhoneNumber; only gets the number. That leaves the line ending still in the input buffer to be read the next time you try to read a line.
Not under standing looping for arrays. Looping through all of grab some or search. Can someone explain the process? Thanks in advance. Sorry if duplicate. I looked around and couldnt find a solid explaination that I could understand.
#include <fstream>
#include <iostream>
#include <string>
#include <cstring>
using namespace std;
void allContacts(string names[], string phones[])
{
cout << "Showing all contacts... Press Q to go back to main menu" << endl;
}
void addName(string names[], string phones[])
{
bool keepGoing;
string input;
beginning:
for (int i = 0; i < sizeof(names); i++)
{
cout << "Enter contact name: ";
cin >> names[i];
cout << "Enter contact number: ";
cin >> phones[i];
cout << "Do you have another contact to add? y or no" << endl;
cin >> input;
if(input == "y" || input == "Y")
{
goto beginning;
}
if(input == "n" || input == "N")
{
cout << "Contacts you have entered: " << endl;
cout << names[i] << " : " << phones[i] << endl;
}
}
}
void searchName(string names[], string phones[])
{
string name;
cout << "Enter Name: ";
cin >> name;
cout << "Search for a name or Press Q to go back to main menu" << endl;
for (int i = 0; i < sizeof(names); i++){
if (name == names[i])
{
cout << counter << names[i] << " 's phone number is: " << phones[i] << endl;
} else {
cout << "No results found";
}
}
}
int main()
{
string names[100];
string phones[100];
int choice;
cout << "============================" << endl;
cout << "=== Welcome to PhoneBook ===" << endl;
cout << "============================" << endl;
cout << "1- Add a New Contact" << endl;
cout << "2- Search By Name" << endl;
cout << "3- Display All" << endl;
cout << "0- Exit" << endl;
cout << "Select a number: " << endl;
cin >> choice;
switch(choice)
{
case 1:
addName(names, phones);
break;
case 2:
searchName(names, phones);
break;
case 3:
allContacts(names, phones);
break;
case 0:
cout << "Exiting PhoneBook...";
break;
}
}
In C++ arrays lose attributes when passed to functions. Those attributes are capacity and size (number of filled slots). You will need to pass this additional information for each array:
void addName(string names[], unsigned int names_capacity, unsigned int names_size,
string phones[], unsigned int phones_capacity, unsigned int phones_size)
To get around this, you can use std::vector. The std::vector knows its capacity and size, so you don't have to pass additional attributes to your function.
Also, if you use tolower or toupper before you compare, you only need to make one comparison:
char input;
cout << "Do you have another contact to add? y or n" << endl;
cin >> input;
input = toupper(input);
if(input == 'Y')
When using strings, you can convert them to all uppercase or all lowercase by using std::transform, such as:
std::transform(input.begin(),
input.begin(), input.end(),
tolower);