CODEWITHSUNDEEP
c++arraysclassdictionaryassociative-array
Ash M
Ash M

Reputation: 55

Programming a custom Map class using an array

I'm trying to program my own implementation of a map class using templates and and not using vectors, only an array.

I have two classes: Element which stores the Key and the data.

template <typename K, typename DT>
class Element
{
  public:
    K key;
    DT data;
};

And the Map class.

Private Variables:

template <typename K, typename DT>
class myMap 
{
   typedef Element<K, DT> myElement;

private:
  myElement  *elements;
  int size;

Constructor:

Template <typename K, typename DT>
myMap<K, DT>::myMap()
{
 //An initial map with a size of 10 potential elements.
 size = 10;
 elements = new myElement[size];    
}

Ok my question is; In my insert method, which adds a new element into the array I'm having problems accessing the elements data from within the array. 

template <typename K, typename DT>
void myMap<K, DT>::insert(const K &key, const DT &val)
{
 /*A temporary element to store the data which is then stored
 in the array.*/
 myElement *temp = new myElement;
 temp->key = key;
 temp->data = val;

 elements[i]->key //This isn't allowed, It's not letting me access the key for the element at I

 delete temp;
}

I can get to it like this:

elements->key;

Basically I need to be able to access the array within the class and access the data from the element class so that I can check if the key is already present to avoid duplication.

Upvotes: 0

Views: 1308

Answers (1)

QuestionC
QuestionC

Reputation: 10064

Use elements[i].key

The elements array is a pointer, but when you array index it, you just get a regular old myElement object.

Usually the compiler's error message is pretty clear on this. I'd go back and reread the error you got.

Upvotes: 2

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