Pointers are very useful data type in C. You can use them to manipulate large arrays or matrices of data, to store strings and colormaps, to keep track of the current position in a file or input stream, or to implement linked lists and trees.

What is a pointer?

A pointer is a data type in C that stores the address of another variable. Pointers are used to store addresses because they can be easily dereferenced to get the value at that memory address.

Pointers can be dereferenced using the * operator. For example, if we have a pointer called ptr that stores the address of an int variable, we can dereference ptr to get the value of the int variable:

int val = 10; int *ptr = &val; printf(“%d”, *ptr); // prints 10 

As you can see, the * operator allows us to get the value stored at the memory address pointed to by a pointer. We can also use the * operator on pointers to change the value of the variable they point to:

int val = 10; int *ptr = &val; *ptr = 20; printf(“%d”, val); // prints 20 

In this example, we’ve changed the value of val from 10 to 20 by dereferencing ptr and assigning it a new value.

What’s the syntax for a pointer in c  ?

The syntax for a pointer in c is quite simple. Just put an * in front of the name of the variable you want to make into a pointer. For example, if you have an int variable named foo, you can make it into a pointer like this:

int *foo;

Once you’ve done that, you can use the variable foo just like any other pointer. You can assign it to another pointer, dereference it with the * operator, and so on.

How to use pointers in C ?

A pointer is a variable that stores the address of another variable. Pointers are commonly used in C programs to manage memory, manipulate strings, and to pass arguments to functions.

When you declare a pointer, you must specify the type of data that it will point to. For example, the following declaration creates a pointer named p that points to an integer:

int *p;

The asterisk (*) in the declaration above is the pointer’s operator. The data type of the variable that p points to (an integer) appears before the asterisk.

You can initialize a pointer when you declare it or you can wait until later to initialize it. For example, the following declarations all initialize p so that it points to the integer variable x:

int x;
int *p = &x;  // & is the address-of operator
int *p = NULL; // NULL is a special constant that represents 
// a null pointer

Simple pointer syntax in C and pseudo code

A pointer is a data type that stores the address of another variable. Pointers are commonly used in C programming to store the address of an array or a function.

The syntax for declaring a pointer in C is to add an asterisk ( * ) before the name of the variable, like so:

int *ptr;

This declares a pointer named ptr that can store the address of an integer variable. The type of data that can be stored in a pointer is determined by the data type that the asterisk ( * ) points to. In the example above, since ptr is declared as an int * , it can only store the address of an integer variable.

Here’s some pseudo code that shows how to use a pointer to store the address of an array:

int arr[5] = {1, 2, 3, 4, 5}; //an array of integers
int *ptr; //a pointer to an integer
ptr = &arr[0]; //store the address of arr[0] in ptr

Now, whenever we dereference ptr (i.e., when we use the * operator on ptr ), we’ll get back the value stored at arr[0

Conclusion

A pointer is a variable that stores the address of another variable. Pointers are used to store addresses because they can be easily dereferenced to access the value of the variable they point to. 

Pointers are a fundamental part of the C programming language and are used extensively in systems programming and other performance-critical applications. When used correctly, pointers can help you write more efficient and reliable code.