c++ - arrays, removeFirst() not working? -

i have created method should remove first element of array, when run code, debugger flips out , i'm not sure why.

this removefirst() method:

loan & listofloans ::  removefirst(){     index = 0;     //determine if container needs shrunk     if((numberofelements < capacity/4) && (capacity >= 4)){ // shrink container when     array 1/4 full         cout<<"shrinking array! \n";         loan ** temp = elements;         elements = new loan * [numberofelements/2];         //copy temp array elements         for(int = 0; i<numberofelements; i++){             temp[i] = elements[i];             numberofelements = numberofelements/2;             delete [] temp;         }     }     numberofelements--;     return **elements; }  

and header file measure:

#include <iostream> #include "loan.h"  using namespace std;  class listofloans {  public: listofloans(int initial_size=4);  ~listofloans(void);    void add(loan & aloan);  loan & first() ;  loan & removefirst();    // answer first element list , remove list     // if resulting list more 3 quarters empty release memory  loan & removelast();     // answer last element list , remove list     // if resulting list more 3 quarters empty release memory  loan & next();  int size();   private:  loan ** elements; //actuall stuff in array m_pndata; int numberofelements; //number of elements in list  stize of array? m_nlength int capacity; //size of available array memory  int index; //used iteration }; 

there many issues code. here annotated copy.

// return reference cannot used if removing element. // looks java-ism. loan & listofloans ::  removefirst(){     // unused variable     index = 0;      if((numberofelements < capacity/4) && (capacity >= 4)){         cout<<"shrinking array! \n";         loan ** temp = elements;         // allocating array of size numberofelements/2...         elements = new loan * [numberofelements/2];          // accessing elements way past end.         for(int = 0; i<numberofelements; i++){             temp[i] = elements[i];             // halving array size in every iteration             numberofelements = numberofelements/2;             // deleting temp in every iteration,             // causing double-frees             delete [] temp;         }     }     // if array not need shrunk,     // removing last element.     // removed element not freed , leaking.     numberofelements--;     // returning first element,     // not removed.     return **elements; } 

i recommend replace listofloans stl container, such std::deque. if can't this, here minimal fixed version.

loan listofloans::removefirst() {     loan to_return;     if (numberofelements == 0) {         return to_return; // return default value, there nothing remove     }     if ((numberofelements < capacity/4) && (capacity >= 4)) {         loan **old = elements;         capacity = capacity / 2;         elements = new loan*[capacity];         (int i=0; < numberofelements - 1; ++i) {             elements[i] = old[i+1];         }         to_return = *old[0];         delete old[0];         delete[] old;     } else {         to_return = *elements[0];         delete elements[0];         (int i=0; < numberofelements - 1; ++i) {             elements[i] = elements[i+1];         }     }     --numberofelements;     return to_return; }