c++ - get function not returning what i expect -

i trying create function in class return take i, j argument , return value of located @ object(i, j).

so far in function converting i, j equivalent in 1d array * (number of columns) + j, in code equal 5. next want show value @ location 5 in array. seems return first value of array, not location 5 value. ideas going wrong? using pointer in wrong way? full program below:

 #include <iostream>     using namespace std;      class mymatrix{      public:         //default constructor set member variables null states         mymatrix();         mymatrix(int sizer, int sizec, double * input_data);                 ~mymatrix();    //destructor          //member functions         int get(int i, int j);      private:         int m;      //rows         int n;      //columns         double * data;     };      int main(){          const int rows = 3;         const int columns = 2;          double * userinput;          cout << "the array 3*2, or 6 elements." << endl;          userinput = new double[rows*columns];         double temp;         (int = 0; < rows*columns; i++){             //let user type in array             cout << "please enter value" << << endl;             cin >> temp;             *(userinput + i) = temp;         }          mymatrix objecta(rows, columns, userinput); //creating object specifications         cout << "the value of objecta 2,1 is: " << objecta.get(2, 1) << endl;           return 0;     }      mymatrix::mymatrix(){         cout << "mymatrix constructor lets go" << endl;         m = 0;         n = 0;         data = 0;     }      mymatrix::mymatrix(int sizer, int sizec, double * input_data){         cout << "mymatrix::mymatrix(int sizer, int sizec, double * input_data) called." << endl; //showing constructor working :)         m = sizer;         n = sizec;          data = new double[m*n];         (int = 0; < m*n; i++){             data[i] = *input_data;         }          cout << "the items have entered are:" << endl;      //printing out array showing array filled         (int = 0; < m*n; i++){             cout << << "item is: " << *(input_data + i) << endl;         }     }      int mymatrix::get(int i, int j){         cout << "getfunction happening" << endl;          //val should k  [k = * n + j]         int val = 0;         val = * n + j;        //n columns, m rows derp         cout << "val equal to: " << val << endl; //so val 5         //how display @ location 5 in object          return data[val]; // shouldnt return 5th element in data?     }       mymatrix::~mymatrix(){         cout << "mymatrix::~mymatrix() invoked" << endl; //showing destructa function working         delete[] data;  //the memory management       } 

use data[i] = input_data[i] instead data[i] = *input_data, , add delete [] userinput free memory or memory leak.