C++

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initializing static vector

May 22, 2012 at 3:51am
jls36 (26)
I have a static vector data member in my class and Im having trouble to initialize it. My vector's data type is another one of my classes which is called Leg. I've tried the ways I used with an int that worked. So not sure what is different about a vector.

Thanks for any help in advance.
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#include <vector>
using std::vector;

#ifndef ShortestRoute_h
#define ShortestRoute_h

// ShortestRoute class definition
class ShortestRoute
{
  public:
    static vector<Leg> legVector;   
    ShortestRoute();

  private: 

};

// ShortestRoute constructor
ShortestRoute::ShortestRoute()
{
} // close constructor


#endif



I've tried in main(), global & in constructor

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ShortestRoute sR;
sR.legVector.push_back( Leg1 );
ShortestRoute::legVector.push_back( Leg1 );
vector<Leg> ShortestRoute::legVector.push_back( Leg1 );
ShortestRoute::legVector = aVector;


Don't know what's wrong or what im doing wrong.

Last edited on May 22, 2012 at 3:52am
May 22, 2012 at 4:28am
SirSmilesaLot (174)
u should initialise it immediately after the class definition
class name::ur vector initialisation
May 22, 2012 at 6:51am
jls36 (26)
I tried this vector<Leg> ShortestRoute::legVector.push_back( Leg1 ); here is the code and the error:
1>ShortestRoute.cpp(156): error C2143: syntax error : missing ';' before '.'


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#ifndef ShortestRoute_h
#define ShortestRoute_h

// ShortestRoute class definition
class ShortestRoute
{
  public:
    static vector<Leg> legVector;   
    ShortestRoute();

  private: 

};

// ShortestRoute constructor
ShortestRoute::ShortestRoute()
{
} // close constructor

const Leg Leg1("San Francisco", "Reno", 218.1);
vector<Leg> ShortestRoute::legVector.push_back( Leg1 );


#endif


also tried ShortestRoute::legVector.push_back( Leg1 );
here is this error:

1>ShortestRoute.cpp(156): error C2143: syntax error : missing ';' before '.'
1>ShortestRoute.cpp(156): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>ShortestRoute.cpp(156): error C2371: 'legVector' : redefinition; different basic types
1>          ShortestRoute.cpp(143) : see declaration of 'legVector'
1>


Thanks for the help.
May 22, 2012 at 9:02am
SirSmilesaLot (174)
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#include<iostream>
#include<conio.h>
#include<vector>
using namespace std;


class abc
{
    public:
    int a;
    float b;
    abc()
    {
        a=0;
        b=1;
    }
};
class xyz
{
public:
 static vector<abc> myvector; 
   xyz();
};
std::vector<abc> xyz::myvector;
xyz::xyz()
{
}
void main()
{
    abc object;
    xyz::myvector.push_back(object);
}
Edit & run on cpp.sh


Modify it as per ur program.If u have any doubts, pls feel free to ask.
May 22, 2012 at 9:20am
cire (8284)
You need to place the definition for legVector in the implementation (.cpp) file for your ShortestRoute class. You cannot push_back() elements outside of a function body.
Last edited on May 22, 2012 at 9:20am
May 22, 2012 at 6:23pm
jls36 (26)
Thanks anirudh sn. That worked so I tried what you showed before except the
std::vector<Leg> ShortestRoute::legVector;. What does this do?

I'm working with one .cpp no .h's all classes are in the same .cpp as main() so no implementation file cire.

Anyway thanks for the help.
Last edited on May 22, 2012 at 6:32pm
May 23, 2012 at 3:54am
SirSmilesaLot (174)

std::vector<Leg> ShortestRoute::legVector;

Since the vector is static it has to be initialised before use else it wont be assigned any memory.

std::vector<leg> informs the compiler about the type of static variable.
ShortestRoute::legVector vector initialisation with class name.
May 23, 2012 at 8:41am
jls36 (26)
cool, Thanks for being helpfull.
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