C++ having input to class - c++

Question

I made 2 function : getdata, print for input/print variable in person class
#include <iostream>
#include <string>
using namespace std;
class person {
public:
char name[19];
int born_year, married_year;
};
void getdata(char* name, int born_year,int married_year) {
cout << "Enter Name!\n > ";
cin.getline(name, 19);
cout << "What's the Born Year?\n > ";
cin >> born_year;
cout << "What's the Married Year?\n > ";
cin >> married_year;
}
void print(char* name, int born_year, int married_year) {
cout << "Your Name : " << *name;
cout << "\n Your Born Year : " << born_year;
cout << "\n Your Married Year : " << married_year;
}
int main(void) {
person p;
int born_year, married_year;
getdata(p.name, p.born_year, married_year);
print(p.name, p.born_year, p.married_year);
return 0;
}
I'm trying to have input in a function outside the class
(class only have variables about person)
and print with with other function.
How could I make this work?

Answer 1

Your problem is in the variable types to your getdata function. The integer parameters need to be pass-by-reference (either pointers or references, the latter being preferred). Right now you pass in a copy of the born_year and married_year values. When you get the input you save that into local variables; the passed parameters are never updated.
You want something like this:
void getdata(char* name, int &born_year,int &married_year)
With that tiny change (adding the two & characters) your code should work as you expect.

Answer 2

#include <iostream>
#include <string>
using namespace std;
class person {
public:
char name[19];
int born_year, married_year;
};
void getdata(char* name, int &born_year, int &married_year) {
cout << "Enter Name!\n > ";
cin.getline(name, 19);
cout << "What's the Born Year?\n > ";
cin >> born_year;
cout << "What's the Married Year?\n > ";
cin >> married_year;
}
void print(char* name, int born_year, int married_year) {
cout << "Your Name : " << name;
cout << "\n Your Born Year : " << born_year;
cout << "\n Your Married Year : " << married_year;
}
int main(void) {
person p;
getdata(p.name, p.born_year, p.married_year);
print(p.name, p.born_year, p.married_year);
return 0;
}

Answer 3

If you want passed variables to be changed inside a function you need to pass them by reference. To do that you need to make some changes in your function definition:
void getdata(char* &name, int &born_year, int &married_year) {
//things you function does
}

Answer 4

Everything looks fine. Just you need to call 'function by reference' to directly change values of class variable.
https://www.tutorialspoint.com/cplusplus/cpp_function_call_by_reference.htm
void getdata(char* name, int born_year,int married_year)
you can remove variables declared in main function and use p. before every parameter.
getdata(p.name, p.born_year, p.married_year);

Answer 5

As others have mentioned your problem was that you were passing copies of the values in, not the variables themselves. Also you forgot to put the "p" on "married_year" in your main loop.
However, rather than passing in the separate values by reference, a much nicer idea is passing in a reference to the whole person:
int main(void) {
person p;
getdata(p);
print(p);
return 0;
}
Getdata and print would look like this:
void getdata(person &p) {
cout << "Enter Name!\n > ";
cin.getline(p.name, 19);
cout << "What's the Born Year?\n > ";
cin >> p.born_year;
cout << "What's the Married Year?\n > ";
cin >> p.married_year;
}
void print(const person &p) {
cout << "Your Name : " << *(p.name);
cout << "\n Your Born Year : " << p.born_year;
cout << "\n Your Married Year : " << p.married_year;
}
It's a cleaner way to do it, and since you're not creating or passing as many variables around, there are less ways to make a mistake here. If you made the fields private however, you'd need to make the two functions "friend" of the class to access its members.