Linked Lists, Objects and Member Functions

[bickelz]

So I'm writing this simple practice program using a linked list where I create a list of employee objects which store their names, age, ect...

I was able to figure out how to create new objects (employees) using the linked list in order to enter the data but I'm having trouble printing out that data. I am able to enter data but nothing is printed out.

My question is how do I access member functions of a class through a linked list of objects (or even a vector while we're at it)?

My code isn't complete because I'm just trying to get it to work with first names before everything else.

#include <iostream>
#include <list>
#include <string>

using namespace std;

class emp_rec {
private:
	string first_name, last_name;
	int age, job_level;
public:
	void set_first_name(string s) {first_name = s;}
	void set_last_name(string s) {last_name = s;}
	void set_age(int n) {age = n;}
	void set_job_level(int n) {job_level = n;}
	string get_first_name() {return first_name;}
	string get_last_name() {return last_name;}
	int get_age() {return age;}
	int get_job_level() {return job_level;}
	void print_first() {cout << first_name << endl;}
	
	
};

int main() {
	
	list<emp_rec> EL;
	list<emp_rec>::iterator iter;
	string first, last;
	int age;
	
	while (true) {
		emp_rec* pt = new emp_rec;
		EL.push_back(*pt);
		cout << "Enter first name. Press ENTER to exit." << endl;
		getline(cin, first);
		if (first.size() == 0)
			break;
		(*pt).set_first_name(first);
	}
	
	for (iter = EL.begin(); iter != EL.end(); iter++) {
		cout << (*iter).get_first_name() << endl;
	}
	

	
	
	
	
	return 0;
}

I also get the same result by replacing
cout << (*iter).get_first_name() << endl;

with

(*iter).print_first();

[ne555]

emp_rec* pt = new emp_rec;
EL.push_back(*pt);
//...
(*pt).set_first_name(first);

push_back() makes a copy, you are not setting the name of the object in the container.

Also, you've got a memory leak there. There is no point in that dynamic allocation.

[bickelz]

Well, if I get rid of the new keyword and just have

emp_rec* pt = emp_rec;

I get a "expected primary expression before ';' error".

So, I'm guessing i will have to use the list::insert function then.

[ne555]

emp_rec temp;
temp.set_first_name("foo");
EL.push_back(temp);

[bickelz]

That works but now I've run into another problem which is that it stops letting me input something into the first name after creating one object so there is no way for me to end the program.

It worked with just the one variable like in the post above and it even worked when I set the variables myself like so...

emp_rec temp;

                cout << "Enter first name." << endl;
		getline(cin, first);
		temp.set_first_name(first);
		temp.set_last_name("Smith");
		temp.set_age(12);

               EL.push_back(temp);

I am able to print out a list like I want.

First
Last
Age

First
Last
Age
.
.
.

But when I ask for user input...

emp_rec temp;
                cout << "Enter first name." << endl;
		getline(cin, first);
                if (first.length() == 0)
                         break;
		temp.set_first_name(first);
		cout << "Enter last name." << endl;
		getline(cin, last);
		temp.set_last_name(last);
		cout << "Enter age." << endl;
		cin >> age;
		temp.set_age(age);

               EL.push_back(temp)

It gives me

Enter first name.
JOhn 
Enter last name.
Smith
Enter age.
23
Enter first name.
JOhn 
Smith
23

and won't let me enter another name.

[ne555]

This is your input
JOhn\nSmith\n23\n
when you do a getline() the '\n' is discarded,
but that is not the case when you do cin>>age;

So a '\n' remains in the buffer, and the program mistake it for the next name (an empty one)

You could simply

cin >> age;
cin.ignore();

[bickelz]

Cool, that did the trick!