this pointer

[1vf9z8AR]

I want the output to display the name and salary of person.I must use 'this' pointer.

#include<iostream>
#include<string.h>
using namespace std;
class salesman
{
private:
        char name[80];
        int pay;
public:
        salesman(char *str,int *p)
        {
                strcpy(name,str);
                pay=p;
        }
        void outdata()
        {
                cout.write(this->name,80);
                cout<<" has salary ";
                cout.write(this->pay);
        }
};

int main()
{
        salesman s1("Raman",4000),s2("Rita",2000);
        s1.outdata();
        s2.outdata();
}

[MikeyBoy]

And? What problem are you having?

You seem to have mistaken this for the telepath forum.

EDIT: I suggest you might find this tutorial helpful:

http://www.cplusplus.com/doc/tutorial/basic_io/

Also, at line 13, I'm sure that's not doing what you want to do. Hint: pay and p are different types.

[1vf9z8AR]

@MikeyBoy
oh sorry lol.

These are the errors i am getting.

||=== Build: Debug in thispointer (compiler: GNU GCC Compiler) ===|
F:\c++projects\thispointer\pointerthis.cpp||In constructor 'salesman::salesman(char*, int*)':|
F:\c++projects\thispointer\pointerthis.cpp|13|error: invalid conversion from 'int*' to 'int' [-fpermissive]|
F:\c++projects\thispointer\pointerthis.cpp||In member function 'void salesman::outdata()':|
F:\c++projects\thispointer\pointerthis.cpp|19|error: no matching function for call to 'std::basic_ostream<char>::write(int&)'|
F:\c++projects\thispointer\pointerthis.cpp|19|note: candidate is:|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\4.9.2\include\c++\bits\ostream.tcc|182|note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::write(const _CharT*, std::streamsize) [with _CharT = char; _Traits = std::char_traits<char>; std::streamsize = int]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\4.9.2\include\c++\bits\ostream.tcc|182|note: candidate expects 2 arguments, 1 provided|
F:\c++projects\thispointer\pointerthis.cpp||In function 'int main()':|
F:\c++projects\thispointer\pointerthis.cpp|24|warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]|
F:\c++projects\thispointer\pointerthis.cpp|24|error: invalid conversion from 'int' to 'int*' [-fpermissive]|
F:\c++projects\thispointer\pointerthis.cpp|10|note: initializing argument 2 of 'salesman::salesman(char*, int*)'|
F:\c++projects\thispointer\pointerthis.cpp|24|warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]|
F:\c++projects\thispointer\pointerthis.cpp|24|error: invalid conversion from 'int' to 'int*' [-fpermissive]|
F:\c++projects\thispointer\pointerthis.cpp|10|note: initializing argument 2 of 'salesman::salesman(char*, int*)'|
||=== Build failed: 4 error(s), 2 warning(s) (0 minute(s), 0 second(s)) ===|

[1vf9z8AR]

These are the errors i am getting.

||=== Build: Debug in thispointer (compiler: GNU GCC Compiler) ===|
F:\c++projects\thispointer\pointerthis.cpp||In constructor 'salesman::salesman(char*, int*)':|
F:\c++projects\thispointer\pointerthis.cpp|13|error: invalid conversion from 'int*' to 'int' [-fpermissive]|
F:\c++projects\thispointer\pointerthis.cpp||In member function 'void salesman::outdata()':|
F:\c++projects\thispointer\pointerthis.cpp|19|error: no matching function for call to 'std::basic_ostream<char>::write(int&)'|
F:\c++projects\thispointer\pointerthis.cpp|19|note: candidate is:|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\4.9.2\include\c++\bits\ostream.tcc|182|note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::write(const _CharT*, std::streamsize) [with _CharT = char; _Traits = std::char_traits<char>; std::streamsize = int]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\4.9.2\include\c++\bits\ostream.tcc|182|note: candidate expects 2 arguments, 1 provided|
F:\c++projects\thispointer\pointerthis.cpp||In function 'int main()':|
F:\c++projects\thispointer\pointerthis.cpp|24|warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]|
F:\c++projects\thispointer\pointerthis.cpp|24|error: invalid conversion from 'int' to 'int*' [-fpermissive]|
F:\c++projects\thispointer\pointerthis.cpp|10|note: initializing argument 2 of 'salesman::salesman(char*, int*)'|
F:\c++projects\thispointer\pointerthis.cpp|24|warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]|
F:\c++projects\thispointer\pointerthis.cpp|24|error: invalid conversion from 'int' to 'int*' [-fpermissive]|
F:\c++projects\thispointer\pointerthis.cpp|10|note: initializing argument 2 of 'salesman::salesman(char*, int*)'|
||=== Build failed: 4 error(s), 2 warning(s) (0 minute(s), 0 second(s)) ===|

[MikeyBoy]

Strangely enough, your compiler is telling you exactly what I told you.

[1vf9z8AR]

name and *str are not different types??

#include<iostream>
#include<string.h>
using namespace std;
class salesman
{
private:
        char name[80];
        int *pay;
public:
        salesman(char *str,int *p)
        {
                strcpy(name,str);
                pay=p;
        }
        void outdata()
        {
                cout.write(this->name,80);
                cout<<" has salary ";
                cout.write(this->pay);
        }
};
int main()
{
        salesman s1("Raman",4000),s2("Rita",2000);
        s1.outdata();
        s2.outdata();
}

[Ihatov]

Nobody is talking about name and str. What MikeyBoy is talking about is p and pay which he has clearly put in bold so I don't know why are you bringing name and *str up?

And the fact of the matter is they are differrent types.
pay is an int
p is a pointer to int

This clearly indicated here:

F:\c++projects\thispointer\pointerthis.cpp|13|error: invalid conversion from 'int*' to 'int' [-fpermissive]

And you have multiple such errors too.
Hint: You actually don't want p to be a pointer at all.

I also suggest the OP to stop treating compilation errors as

my code doesn't work

and instead view them as useful hints on where things might have gone wrong.

[1vf9z8AR]

i thought if pay and *p are different then so must be name and *str.

[1vf9z8AR]

For this
cout.write(this->*pay);
i get this
F:\c++projects\thispointer\pointerthis.cpp|19|error: '((salesman*)this)->salesman::pay' cannot be used as a member pointer, since it is of type 'int*'|

how do i get around this one?I tried float but similar error comes

[MikeyBoy]

i thought if pay and *p are different then so must be name and *str.

But pay and *p are the same type.

pay and p are different types.

I have a feeling that the real problem is that you don't really understand pointers, nor the syntax for declaring and using them. I'd recommend going back to your textbook, and getting a clearer understanding of that chapter.

[1vf9z8AR]

my textbook is really bad for pointers so are the online resources(too advanced).Do you know any study material online for just the basics of pointers?Unfortunately i am not able to devote time to computer science because of my main subjects physics chemistry maths.

[Repeater]

http://www.cplusplus.com/articles/EN3hAqkS/

[Ihatov]

Do you know any study material online for just the basics of pointers?

Where do you think you are?

http://www.cplusplus.com/doc/tutorial/pointers/

This tutorial was written for somebody who has never heard about pointers in their life.
If this is too advanced for you then you're just not trying hard enough.

[1vf9z8AR]

ooooooh thanks. I didnt know the meaning of tutorial so i didnt notice it.