Standard C vector

//http://www.youtube.com/user/thecplusplusguy
//standard C vector
#include <stdio.h>
#include <stdlib.h>


typedef struct _vector{
void* array;
int size;
int capacity;
int elementSize;

} vector;

vector* initVector(int elementSizeInBytes)
{
    vector* v=(vector*)malloc(sizeof(vector));
    v->capacity=16; //start from 16 element
    v->size=0;
    v->elementSize=elementSizeInBytes;
    v->array=malloc(v->capacity*v->elementSize);
    return v;
}

vector* freeVector(vector* v)
{
   free(v->array);
   free(v);
}

void pushBackVector(vector* v,void* element)
{
    int startIndex=v->size*v->elementSize;
    void* pointer;  //older C standard required you, to declare variables at the begginning
    int i;
    if(v->size>=v->capacity)
    {
        pointer=malloc(v->capacity*2*v->elementSize);
        for(i=0;i<v->capacity*v->elementSize;i++)
            ((char*)pointer)[i]=((char*)v->array)[i];
        v->capacity=v->capacity*2;
        free(v->array);
        v->array=pointer;
    }
    for(i=0;i<v->elementSize;i++)
        ((char*)v->array)[startIndex+i]=((char*)element)[i];
    v->size++;
}

void* getVector(vector* v,int i)
{
    return (void*)(&((char*)v->array)[i*v->elementSize]);
}

int getSizeVector(vector* v)
{
    return v->size;
}

int main()
{
    int i;
    double d;
    vector* v;
    v=initVector(sizeof(int));
    for(i=0;i<=100;i+=5)
        pushBackVector(v,&i);
    for(i=0;i<getSizeVector(v);i++)
    {
        printf("%d ",*((int*)getVector(v,i)));
    }
    printf("\n");
    freeVector(v);


    v=initVector(sizeof(double));
    for(d=0.0;d<=10.0;d+=0.5)
        pushBackVector(v,&d);
    for(i=0;i<getSizeVector(v);i++)
    {
        printf("%lf ",*((double*)getVector(v,i)));
    }
    printf("\n");
    freeVector(v);

}