getting error:error: no matching function for call to 'Supervisor::Supervisor()' Supervisor s1;

[ahaana]

#include <iostream>
#include<iomanip>
using std::ios;
using std::setiosflags;
using std::setprecision;
using std::ostream;
using std::cout;
using std::endl;


class Time
{
public:
Time(int =0,int =0,int =0);
void setTime(int,int,int);
void setHour(int);
void setMinute(int);
void setSeconds(int);
int getHour() const;
int getMinute() const;
int getSeconds() const;
void printMilitary() const;
void printStandard();
private:
int hour,minute,seconds;

};
Time::Time( int h,int m,int s)
{
setTime(h,m,s);

}
void Time::setHour(int h)
{
hour=h;
}
void Time::setMinute(int m)
{
minute=m;
}
void Time::setSeconds(int s)
{
seconds=s;
}
void Time:: setTime(int h,int m,int s)
{
cout<<(hour<24?"0":" ")<<":"<<(minute<59?"0":" ")<<":"<<(seconds<59?"0":" ");

}
int Time::getHour() const
{
return hour;

}
int Time::getMinute() const
{
return minute;

}
int Time::getSeconds() const
{
return seconds;
}

class Date: public Time
{
public:
Date( int = 0, int = 0, int = 0);
void print() const ;
~Date();
int setdate(int,int,int);
private:
int month;
int day;
int year;
int checkDay( int);
};
Date::Date(int dt,int mn,int yr)
{
setdate(dt,mn,yr);

}
int Date::checkDay(int dt)
{
cout<<(dt<31?"0":"");
}
int Date::setdate( int dt,int mn,int yr)
{
day=dt;
month=mn;
year=yr;
cout<<day<<"-"<<month<<"-"<<year;
}
class Project:public Time
{
public:
~Project();
Project(char);
void setProject(char );

};
Project::Project(char pname)
{
setProject(pname);
}
void Project::setProject(char nm)
{
cout<<"Project Name-"<<nm;
}
class Supervisor
{
public:
~Supervisor();
Supervisor(char);
void setnm(char n)
{
cout<<"Supervisor Name-"<<n;
}

};
Supervisor::Supervisor(char n)
{
setnm(n);
}
class Student:public Date
{
public:
~Student();
double setStudent(int,char);
Student(int,char);
protected:
int ID;
char sname;
};
Student::Student(int id,char nme)

{
setStudent(id,nme);
}
double Student::setStudent( int id,char nme)
{
cout<<"Student Name-"<<nme<<endl;
cout<<"ID-"<<id;
}
int main()
{
Time t;
t.setTime(10,20,2);
Date d;
d.setdate(20,03,2018);
Supervisor s1;
s1.setnm('jack');
Student st;
st.setStudent(213,'joe');
}

[Repeater]

Supervisor s1;
This is an attempt to use the default constructor. The constructor function that looks like this:
Supervisor::Supervisor()

There is no such function defined. You can't use functions that don't exist.

[ahaana]

so how should it can be rectified?

[Repeater]

Write that function in your Supervisor class, or don't try to call it.

[Repeater]

s1.setnm('jack');

This line makes no sense also. The ' ' should go around a single (ONE) character, but you're using illegal syntax to try to put it around four characters.

That function takes a single char. ONE char. But you're trying to make it take FOUR char. See the problem?

[ahaana]

okay thanks

[keskiverto]

First of all, please use code tags when posting code. See http://www.cplusplus.com/articles/jEywvCM9/

Your code:

class Supervisor
{
public:
  ~Supervisor();
  Supervisor(char);
  void setnm(char);
};

int main()
{
  Supervisor s1; // error: no constructor that takes 0 arguments.
}

Your class has three members:
1. Destructor
2. Constructor that takes 1 char argument
3. setnm() function that takes 1 char argument

A constructor that takes no arguments is called default constructor.
If a class has no constructors, then compiler generates default constructor.


You could:

1. Use the existing constructor:

int main()
{
  Supervisor s1('x'); // calls Supervisor::Supervisor(char)
}

2. Force compiler to create the default constructor

class Supervisor
{
public:
  ~Supervisor();
  Supervisor() = default;
  Supervisor(char);
  void setnm(char);
};

3. Explicitly define the default constructor:

class Supervisor
{
public:
  ~Supervisor();
  Supervisor();
  Supervisor(char);
  void setnm(char);
};

Supervisor::Supervisor()
// member initializer list
{
  // code
}

PS 'jack' and 'joe' are not proper char. Single quotes hold one char.
"jack" and "joe" are not char either. They are constant C-string literals.

[ahaana]

bt by double " " they are showing error

[Repeater]

bt by double " " they are showing error

"jack" will work for a function that expects a char-pointer. But all this is a waste of time. Just use string

[Repeater]

Just use string.