int x;
Person me;
Person *p;
Person people[100];
Person(); //an anonymous stack object;
foo( Person() ); //creating a temporary function argument
 

The following statements declare memory on the Heap (Dynamic Memory)
Dynamic memory is allocated in any statement of the form: new Type

int * i = new int;
Person *p = new Person("Lou");
Person *p = new Person[100];

Note: the following statements are equivalent

Person* p;
Person * p;
Person  *p;

The following statements are NOT equivalent

Person* p,q;
Person *p, *q;

...later

delete p;

BankAccount * accounts = new BankAccount[100];
//Will require a default BankAccount constructor

...later

delete [] accounts

//example for allocating, using, and deleting a 3*5
//dynamic array

#include <iostream>
using namespace std;

 
int main(void) {

   int **a; //pointer to int *

   //allocate dynamic 3*5 array
   a = new int*[3];
   for (int i=0; i<3;i++)
      a[i] = new int[5];

   //put some numbers in the array
   for (i = 0; i<3; i++)
      for (int j = 0; j<5; j++)
        a[i][j] = i * j;

   //print the array
   for (i = 0; i<3; i++) {
    for (int j = 0; j<5; j++)
       cout << a[i][j];
    cout << "\n";
  }

   //delete the dynamic array
   for(i = 0; i<3;i++)
    delete [] a[i];
   delete [] a;

   return 0;
}

Using C-style Strings (Example)

#include <iostream>
#include <cstring> //for strcmp(), strcpy(), strlen(), strcat()

using namespace std;

int main() {
     char input[100];
     char * myString;
    
     cout << "enter an input string" << endl;
     cin >> input;
     cout << "you said: ";
     cout << input << endl;
     cout << "the length of your string is " << strlen(input) << endl;
    
     myString = new char[strlen(input) + 1];
     strcpy(myString, input);
    
     cout << "the length of myString is " << strlen(myString) << endl;
     cout << myString << endl;
    
     //comparing strings
     cout << strcmp("abba", myString) << endl;
     cout << strcmp(myString, myString) << endl;
     cout << strcmp(myString, "abba") << endl;
   
     return 0;

/* Program output

enter an input string
Saturday
you said: Saturday
the length of your string is 8
the length of myString is 8
Saturday
1
0
-1

*/

Example of Dynamic Memory for C-style string variables in a class

#include <iostream>
#include <cstring> //for strcmp(), strcpy(), strlen(), strcat()

using namespace std;

class Person {
public:
   Person(char * their_name = "unknown", char * email = "unknown"){
      name = new char[strlen(their_name) + 1];
      strcpy(name, their_name);
      email_address = new char[strlen(email) + 1];
      strcpy(email_address, email);
   }

   ~Person(void) {
      delete [] name;
      delete [] email_address;
   }

   char * getEmailAddress(){return email_address;}
   char * getName() {return name;}

private:
   char * name;
   char * email_address;
};

void main(){
      Person lou("Lou", "lou@hotmail.com");
      Person sue("Sue", "sue@scs.carleton.ca");
      Person p;
      cout << lou.getName() << " email: " << lou.getEmailAddress() << endl;
      cout << sue.getName() << " email: " << sue.getEmailAddress() << endl;
      cout << p.getName() << " email: " << p.getEmailAddress() << endl;
}