C Programming: Functions, Pointers, and Arrays

Study Notes

C Programming

Functions

In C programming, a function is a block of organized, reusable code that performs a single, related action. A function may also return values from multiple outputs. There are two types of functions in C:

User Defined Functions

User-defined functions allow you to define your own functions according to your needs. They can have any name you choose, depending on your convenience. These functions do not come with predefined libraries like printf() and scanf(). Users need to create their own user-defined functions by using the following syntax:

return_type function_name(parameters)
{
   // code here
}

Standard Library Functions

Standard library functions in C are predefined functions that are available in the standard library. These functions are built-in and you don't need to manually define them. Examples of standard library functions include printf() and scanf().

Pointers

Pointers in C programming are variables that hold the memory addresses of other variables. They can store the memory addresses of any data type. The syntax for declaring a pointer is as follows:

data_type *pointer_name;

Pointer Operations

C programming supports various pointer operations, including:

Pointer Arithmetic: Pointers can be used for arithmetic operations. This is because a pointer, like any other variable, can be incremented or decremented.
Pointer Dereference: Pointer dereference is the process of accessing the value stored at the memory location pointed to by a pointer.
Pointer Assignment: You can assign one pointer to another, copying its value.
Pointer Comparison: Pointer comparison allows you to compare pointers. The result of the comparison will be true if the two pointers point to the same memory location.

Arrays

An array in C is a collection of elements of the same data type. Each element is stored in a contiguous block of memory. Arrays are used to store large amounts of data and can be accessed using an index.

Array Syntax

Arrays are defined using the following syntax:

data_type array_name[array_size];

The size of the array is fixed at compile time. It cannot change during runtime.

Accessing Array Elements

To access elements of an array, you use the index of the element within the square brackets of the array. For example:

int arr[] = {1, 2, 3};
printf("%d", arr); // Output: 1

Null Terminated String

A null terminated string is a sequence of characters followed by a null character '\0' which marks the end of the string. In C, strings are often represented as null terminated byte strings.

Description

This quiz covers the concepts of functions, pointers, and arrays in C programming. It explains user-defined functions and standard library functions, pointers and their operations like arithmetic, dereference, assignment, and comparison, as well as arrays, array syntax, accessing array elements, and null-terminated strings.