class MyClass1 {
public:
    MyClass1() {
        printf( "constructorn" );
    }
    ~MyClass1() {
        printf( "destructorn" );
    }
    int var1;
    std::string str;
};

std::vector< MyClass1 > testArr;

MyClass1 gr1;

gr1.var1 = 111;
testArr.push_back( gr1 );

gr1.var1 = 122;
testArr.push_back( gr1 );

printf( "testArr.at( 1 ).var1 = %in", testArr.at( 1 ).var1 );

#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

class MyClass1 {
public:
    MyClass1() {
        printf( "constructorn" );
    }
    ~MyClass1() {
        printf( "destructorn" );
    }
    int var1;
    string str;
};

int main()
{
    vector< MyClass1 > testArr;

    MyClass1 gr1;

    gr1.var1 = 111;
    testArr.push_back( gr1 );

    gr1.var1 = 122;
    testArr.push_back( gr1 );

    printf( "testArr.at( 1 ).var1 = %in", testArr.at( 1 ).var1 );

   return 0;
}

constructor
destructor
testArr.at( 1 ).var1 = 122
destructor
destructor
destructor