Unlocking the Power of Pointers in C++
Memory Addresses: The Hidden Key
Every variable in a C++ program has a secret identity – its memory address. This unique location in memory is where the variable’s value is stored. By using the ampersand symbol (&), we can uncover this hidden address. For instance, if we have a variable var, &var returns its memory address.
A Peek into Memory
Take a look at this example:
Output:
0x61ff04
0x61ff08
0x61ff0c
Notice how each address differs from the previous one by 4 bytes? That’s because the size of an int is 4 bytes in a 64-bit system.
Declaring Pointers: The Gateway to Memory
Pointers are variables that store memory addresses of other variables. We can declare pointers in two ways:
int* point_var;
or
int *point_var;
Both declarations create a pointer point_var that points to an int variable.
Assigning Addresses: The First Step
To assign an address to a pointer, we use the ampersand symbol (&) to get the memory address of a variable, and then assign it to the pointer:
int var = 5;
int* point_var = &var;
Uncovering the Value: The Dereference Operator
To get the value stored at the memory address pointed by a pointer, we use the dereference operator (*). For example:
int var = 5;
int* point_var = &var;
cout << *point_var; // Output: 5
Changing the Value: The Power of Pointers
If a pointer points to the address of a variable, we can change the value of that variable using the dereference operator:
int var = 5;
int* point_var = &var;
*point_var = 10; // var is now 10
Common Pitfalls: Avoiding Mistakes
When working with pointers, it’s essential to avoid common mistakes. For instance, be careful when assigning addresses to pointers:
int var;
int* point_var = &var; // Error: var is not initialized
By understanding how pointers work and avoiding common mistakes, you can unlock the full potential of C++ programming.