Basics of C++ Pointers and Examples with Strings

What is a pointer?

A pointer is a variable that stores the memory address as its value.

‘&’ is used to get the memory address of the variable.

‘*’ is used to store the memory address of the variable.

How are pointers used?

Here is an example of how to use a pointer in cpp. A variable is first declared with the string “Pizza”. The memory address of the variable ‘food’ is retrieved with ‘&’. How do we store a pointer into a variable? The ‘*’ symbol is used.

Therefore, in this example ‘ptr’ and &food have the same output, the memory address of the string ‘food’.

#include <iostream>
#include <string>
using namespace std;
int main() {
  string food = "Pizza";  // A string variable
  string* ptr = &food;  // A pointer variable that stores the address of food
// Output the value of food
  cout << food << "\n";
// Output the memory address of food
  cout << &food << "\n";
// Output the memory address of food with the pointer
  cout << ptr << "\n";
  return 0;
}

Output

Pizza
0x7ffd9c804110
0x7ffd9c804110

How are pointers declared?

string* mystring; // Preferred
string *mystring;
string * mystring;

There are 3 ways to declare pointers. The first way is the most preferred.

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