vectors with structure

[srvolatile]

Hi,

I have two structs like below,

struct SP
{
string sp1;
string sp2;
};


struct SL
{
string sl1;
string sl2;
string sl3[3];
vector<SP> sl4;
};

vector<SL> slVect;


Please suggest, How to add data to slVect ?

Thanks in advance.

[VictorN]

Please suggest, How to add data to slVect ?

struct SP
{
    string sp1;
    string sp2; 
};


struct SL
{
    string sl1;
    string sl2;
    string sl3[3];  
    vector<SP> sl4;
};

vector<SL> slVect;

SL slNew;
slVect.push_back (slNew);

[2kaud]

In what circumstances do you want to add data? As part of a processing loop? As initial data? From a file?

[srvolatile]

Hi,

Thanks for your help VictorN.

SL slNew;
slNew.sl1 = "S1";
slNew.sl2 = "S2";
slNew.sl3[0] = "S31";
slNew.sl3[1] = "S32";
slNew.sl3[2] = "S33";
SP spNew;
spNew.sp1 = "sp1";
spNew.sp2 = "sp2";
slNew.sl4.push_back(spNew);
slVect.push_back (slNew);


for (vector<SL>::iterator it = slVect.begin() ; it != slVect.end(); ++it)
{
cout << it->sl1 << "\n";
cout << it->sl2 << "\n";
cout << it->sl3[0] << "\n";
cout << it->sl3[1] << "\n";
cout << it->sl3[2] << "\n";
};

The above code output is as expected and I am facing trouble to access the data of slVect.sl4.
Could you please suggest me, how to access the data from slVect.sl4 ? // I was getting error: "member is not available"
Is it possible to add more data to slVect.sl4 (adding the data using push_back) at the slVect iterator 1 (I mean after the statement : slVect.push_back (slNew))?

Thanks in advance.

Hi 2kaud,
In what circumstances do you want to add data? As part of a processing loop? As initial data? From a file?

I am trying to understand STL Vectors and it isn't part of any project. Consider it as a initial data. Thanks for your reply.


Note: Sorry, if you find any mistakes in my question.

[Philip Nicoletti]

You can access using:

for (vector<SP>::const_iterator it4=it->sl4.begin(); it4!=sl4.end(); ++it4)
{
      cout << it4->sp1 << " : " << it4->sp2 << "\n";
}

For readability, I sometimes do the following:

const vector<SP> & sl4 = it->sl4;  // note reference

for (vector<SP>::const_iterator it4=sl4.begin(); it4!=sl4.end(); ++it4)
{
      cout << it4->sp1 << " : " << it4->sp2 << "\n";
}

I made it a const (and const_iterator) since the vector is not being changed.
And a reference since you do not want to copy the vector.

[srvolatile]

Thanks for your help, Philip Nicoletti .

[2kaud]

If you are using c++11 then you can also simply the iterator access using auto and range based for statement. For initializing the vector if you have constructors for the struct it can make things a little easier and also you can overload the << operator for the structs. eg

#include <vector>
#include <string>
#include <iostream>
using namespace std;

struct SP
{
	string sp1;
	string sp2;

	SP(string s1, string s2) : sp1(s1), sp2(s2){}
	SP(){}
};

ostream& operator <<(ostream& os, const SP& sp)
{
	return (os << sp.sp1 << " : " << sp.sp2 << endl);
}

typedef string ar3[3];
typedef vector<SP> vsp;

struct SL
{
	string sl1;
	string sl2;
	ar3 sl3;
	vsp sl4;

	SL() {}
	SL(const string& s1, const string& s2, string s3[3], const vsp& s4) : sl1(s1), sl2(s2), sl4(s4) {
		sl3[0] = s3[0];
		sl3[1] = s3[1];
		sl3[2] = s3[2];
	}
};

ostream& operator<<(ostream& os, const SL& it)
{
	os << it.sl1 << "\n";
	os << it.sl2 << "\n";
	os << it.sl3[0] << "\n";
	os << it.sl3[1] << "\n";
	os << it.sl3[2] << "\n";

	for (const auto& it4 : it.sl4)
		os << it4;

	return os;
}

int main()
{
	vector<SL> slVect;
	vsp sp;
	sp.push_back(SP("sp1", "sp2"));
	sp.push_back(SP("sp3", "sp4"));
	slVect.push_back(SL("s1", "s2", ar3{ "s30", "s31", "s32" }, sp));
	
	for (const auto& it : slVect)
		cout << it;
}