How to create a dynamic array of integers

The answers above are all good for assigning one-dimensional int-arrays. Anyhow, I want to add that it is also possible to do this for multi-dimensional arrays you'd normally define like int[][] matrix = {{1,2}, {3,4}}.

The key is that you dynamically store all elements in one array and make use of the fact that the array is a continuous block in memory (see here for a clarification of "block"), meaning that you can "slice" yourself through dimensions. Below you can see an example for a 2d-array.

You can find a discussion regarding this topic here on SO.

/*Defining a 2d-matrix.*/
struct Matrix {

    int rows, columns;
    int* matrix;

    Matrix(int rows, int columns) : rows(rows), columns(columns) {
        // Keep in mind that arrays cannot be generated during runtime
        // since the compiler needs to know the size to allocate in memory.
        // Thus, use dynamic memory and keep in mind to delete it!

        // This only uses a single array since "new" cannot create 
        // multidimensional arrays by default. Thus, everything is
        // written in a single memory-block and accessed via getElement().
        matrix = new int[columns * rows];
    }

    ~Matrix() {
        // Release the memory after destroying the Matrix-object
        delete matrix;
    }

    /*Access the element at position [r]ow and [c]olumn.*/
    int getElement(int r, int c) {
        // matrix[c][r] is rewritten as matrix[column + columns * rows] 
        // -> matrix <=> Single memory block
        return matrix[c + columns * r];
    }

    /*Set the element at position [r]ow and [c]olumn with given [val]ue.*/
    void setElement(int r, int c, int val) {
        matrix[c + columns * r] = val;
    }
};

An example to populate such a Matrix-object would be:

    /*Initialize the matrix with the continuous numbers 0..N*/
    void Matrix::initDummyMatrix(){
        int counter = 0;
        for (int row = 0; row < rows; ++row) {
            for (int col = 0; col < columns; ++col) {
                setElement(row, col, counter++);
            }
        }
    }

#include <stdio.h>
#include <cstring>
#include <iostream>

using namespace std;

int main()
{

    float arr[2095879];
    long k,i;
    char ch[100];
    k=0;

    do{
        cin>>ch;
        arr[k]=atof(ch);
        k++;
     }while(ch[0]=='0');

    cout<<"Array output"<<endl;
    for(i=0;i<k;i++){
        cout<<arr[i]<<endl;
    }

    return 0;
}

The above code works, the maximum float or int array size that could be defined was with size 2095879, and exit condition would be non zero beginning input number