C++ class not printing? [closed] - c++

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I'mm getting a bit confused why this isn't printing the name!
I've got a human.cpp :
#include <string>
#include <iostream>
#include "human.h"
human::human(int age, human *n){
m_age=age;
name = new char[2];
human::~human() = default;
void human::printDetails(){
std::cout <<"name is " << name << " age is " << m_age << std::endl;
}
and human.h:
class human {
public: //: needed
human(int age, human *name);
~human();
void printDetails();
private :
char *name;
int m_age;
};
and finally the main.cpp:
#include <iostream>
#include <string>
#include "human.h"
int main()
{
human *Alex = new human(10, Alex); //pointer // needs argument //should have both age and name
Alex->printDetails(); //print not Print
}
So my issue is: it prints the age, but does not print the name? Any suggestions? Thanks :)

Answer 1

There is no need for any new in your code. Since you #included <string> in your code I assume you want to use it:
#include <string>
#include <iostream>
class Person
{
int age;
std::string name;
public:
Person(int age, std::string name)
: age { age },
name { name }
{}
int get_age() const { return age; }
std::string const& get_name() const { return name; }
void print_details() const {
std::cout << "My name is " << name << ". I am " << age << " years old.\n";
}
};
int main()
{
Person p{ 19, "Alex" };
p.print_details();
}
If you *really* want to do it the hard waytm:
#include <cstring> // std::strlen()
#include <utility> // std::exchange(), std::swap()
#include <iostream>
class Person
{
char *name_;
int age_;
public:
Person(int age, char const *name) // constructor
// we don't want to call std::strlen() on a nullptr
// instead allocate just one char and set it '\0'.
: name_ { new char[name ? std::strlen(name) + 1 : 1]{} },
age_ { age }
{
if (name)
std::strcpy(name_, name);
}
Person(Person const &other) // copy-constructor
: name_ { new char[std::strlen(other.name_) + 1] },
age_ { other.age_ }
{
std::strcpy(name_, other.name_);
}
Person(Person &&other) noexcept // move-constructor
: name_ { std::exchange(other.name_, nullptr) }, // since other will be
age_ { other.age_ } // wasted anyway, we
{} // "steal" its resource
Person& operator=(Person other) noexcept // copy-assignment operator
{ // since the parameter other got
std::swap(name_, other.name_); // copied and will be destructed
age_ = other.age_; // at the end of the function we
return *this; // can simply swap the pointers
} // - know as the copy&swap idiom.
~Person() { delete[] name_; } // destructor
void print_details() const
{
std::cout << "I am " << name_ << ". I am " << age_ << " years old.\n";
}
};
int main()
{
Person p{ 19, "Alex" };
p.print_details();
}
If you don't want to implement the special member functions you'd have to = delete; them so the compiler-generated versions - which won't work correctly for classes managing their own resources - won't get called by accident.

Answer 2

#include <iostream>
#include <cstring>
#include <new>
using namespace std;
class human {
public:
human(int age, const char * name)
{
m_age=age;
m_name = new char[strlen(name)+1];
strcpy(m_name,name);
}
~human()
{
delete[] m_name;
}
void printDetails()
{
std::cout <<"name is " << m_name << " age is " << m_age << std::endl;
}
private :
char *m_name;
int m_age;
};
int main()
{
human *Alex = new human(10, "alex"); //pointer // needs argument //should have both age and name
Alex->printDetails(); //print not Print
delete Alex;
return 0;
}
You need to read more. The example you shared was wrong at many level, also read about dynamic memory management.

Answer 3

I guess you're confused with the second parameter of the human constructor. Look at this changes:
human.h
class human {
public:
human(int age, char *name);
human(const human& h);
human& operator=(const human& h);
void printDetails();
virtual ~human();
private:
int age;
char *name;
};
human.cpp
human::human(int _age, char *_name) {
age = _age;
name = new char[strlen(_name)+1];
strcpy(name, _name);
}
human::human(const human& _h) { //Copy constructor
age = _h.age;
name = new char[strlen(_h.name)+1];
strcpy(name, _h.name);
}
human& human::operator=(const human& _h) { //Copy assignment operator
age = _h.age;
name = new char[strlen(_h.name)+1];
strcpy(name, _h.name);
return *this;
}
void human::printDetails(){
std::cout <<"name is " << name << " age is " << age << std::endl;
}
human::~human() { //Destructor
delete[] name;
}
main.cpp
int main() {
human *alex = new human(10, "Alex");
alex->printDetails();
human *anotherAlex = new human(*alex);
anotherAlex->printDetails();
delete alex;
delete anotherAlex;
}
A suggestions: I would use Human as the class names and alex for the variable names. (See how I capitalized them)

Answer 4

For beginner you may use std::string, so you already included it. ))
human.h
#include <string>
class human
{
public: //: needed
human(int age, std::string name);
void printDetails();
private :
std::string name;
int m_age;
};
human.cpp
#include <iostream>
#include "human.h"
human::human(int age, std::string n)
{
m_age = age;
name = n;
}
void human::printDetails()
{
std::cout <<"name is: " << name << " age is: " << m_age << std::endl;
}
main.cpp
#include "human.h"
int main()
{
human *Alex = new human(10, "Alex");
Alex->printDetails();
}