Chapter 3.19: Free Store Operators new and delete

Adapted from: “Object-Oriented Programming Using C++” by Ira Pohl (Addison- Wesley)

Program that demonstrates the free store operators new and delete in C++¶

#include <iostream>
#include <assert.h>
using namespace std;

double avg_arr(const int a[], int size)
{
    int sum = 0;
    for (int i = 0; i < size; ++i)
        sum += a[i];
    return static_cast<double>(sum) / size;
}

int main()
{
    int *   data;
    int     size;

    for (int n_loop = 0; n_loop < 1; ++n_loop) {
        cout << "\nEnter array size: ";
        cin >> size;
        assert(size > 0);

        data = new int[size];
        assert (data != 0);

        for (int j = 0; j < size; ++j) {
            cout << "\nEnter data at position " << j << " -> ";
            cin >> data[j];
        }
        
        cout << " average is " << avg_arr(data, size) << endl;
        delete [] data;
    }
}

Compile and Execute the Program¶

The above program is compiled and run using Gnu Compiler Collection (g++):

import os
root_dir = os.getcwd()

code_dir = root_dir + "/" + "Cpp_Code/Chapter_3_19_Free_Store_Operators_new_and_delete"

ch_dir_stat = os.chdir(code_dir)

build_command = os.system("g++ dynarray.cpp -w -o dynarray")

exec_status = os.system("echo \"5 123 456 789 321 654\" | ./dynarray")


Enter array size: 
Enter data at position 0 -> 
Enter data at position 1 -> 
Enter data at position 2 -> 
Enter data at position 3 -> 
Enter data at position 4 ->  average is 468.6