Dynamical Char Arrays

[thephysicsguru]

I had a question concerning the use of dynamic char arrays with the constructor of a class. Here, I have a class in which I pass a name that will be stored in a dynamically created char array. Since the array size can vary depending on the name passed to the constructor, I am not sure what steps to use to allocate the correct array size. I wish to avoid using string and the STL. Here is what I have so far and it's almost complete except for the name.

/* 
 * Employee.h
 *
 *  Created on: Feb 11, 2012
 *      Author: LEC
 */
#ifndef EMPLOYEE_H_
#define EMPLOYEE_H_

#include <string>

using std::string;

class Employee
{

public:
	Employee();
	~Employee();
	Employee(const char *, int, int);
	void evaluate ();
	double computeEvaluationAverage();


private:
	const char *m_name;
	int m_salary;
	int m_numOfEvaluations;
	int *m_evaluations;

public:

	// mutators

	// accessors
	int getNumOfEvaluations();
	int getSalary();
	string getName();
};

#endif 

/*
 * Employee.cpp
 *
 *  Created on: Feb 11, 2012
 *      Author: lec
 */
#include <iostream>
#include <string>
#include <cstdlib>
#include "Employee.h"

using namespace std;

// default constructor
Employee::Employee()
{

} /* end default constructor */

Employee::Employee(const char * Name = "Employee_Name", int Salary = 0, int numOfEvaluations = 0)
{

m_name = Name;
m_salary = Salary;
m_numOfEvaluations = numOfEvaluations;

} /* end Employee(char *, int, int) */

Employee::~Employee()
{
	string deleteEmployee("deleting employee ");
	cout << deleteEmployee << getName() << endl;

	// clean up
	delete [] m_name;
	m_name = NULL;

	delete [] m_evaluations;
	m_evaluations = NULL;
}

void Employee::evaluate()
{
	m_evaluations = new int [getNumOfEvaluations()];

	for (int i = 0; i < getNumOfEvaluations(); ++i)
	{
		m_evaluations[i] = rand()%101;
	} /* for */

} /* end evaluate() */

double Employee::computeEvaluationAverage()
{
	double sum = 0;

	for (int i = 0; i < getNumOfEvaluations(); ++i)
	{
		sum += m_evaluations[i];
	}

	return (sum / getNumOfEvaluations());

} /* end computeEvaluationAverage() */

// Accessors and Mutators

string Employee::getName()
{
	string name = m_name;
	return name;
} /* end getName() */

int Employee::getSalary()
{
	return m_salary;
} /* end getSalary */

int Employee::getNumOfEvaluations()
{
	return m_numOfEvaluations;
} /* end getNumOfEvaluations */

/*
 * Driver.cpp
 *
 *  Created on: Feb 11, 2012
 *      Author: lec
 */
#include <iostream>
#include <cstdlib>
#include <string>

#include "Employee.h"

using namespace std;

int main ()
{
	srand(time(0));

	char name[] = "John Smith";
	int salary = rand();
	int evaluations = rand()%10;

Employee firstEmployee(name, salary, evaluations);

firstEmployee.evaluate();
cout << firstEmployee.computeEvaluationAverage() << endl;

	return 0;
} /* end main */

Thanks in advance,

L

[Ben Duncan]

Alright, first thing is first: Don't you dare call yourself L. I will write your name down, for you see, I have the eyes; I can see your name above your post. (Seriously though, it's stupid)

Anyway, why on Earth would you want to avoid the ease of strings? The STL too? WHY!?

I cannot think of any way to just take the number of elements from an array. You'd have to use something like vectors, or strings.


_{What the hell? Remove strings is one thing, but to put an end to things like iterators, no.}

[Disch]

strlen is what you want.

const char foo[] = "whatever";
int foolen = strlen( whatever );

char* bar = new char[ foolen + 1 ];  // add 1 for the null terminator!
strcpy( bar, foo );  // copy foo to bar 

I wish to avoid using string and the STL

May I ask why? No point in making things harder on yourself.

[thephysicsguru]

As part of an algorithm class, we are studying how someone might create an algorithm to do, for example, what a string might do. It is the instructor's request NOT to use string and the STL and I quote, "...if you do you will get zero points." Sounds like a good enough reason to me.

[thephysicsguru]

Thanks Disch, that worked great.