C Programming

Introduction to C Programming

C is a powerful general-purpose programming language. It is fast, portable, and available on all platforms. If you are new to programming, C is a good choice to start your programming journey.

Topics Covered

• Basic Syntax
• Data Types
• Control Structures
• Functions
• Arrays
• Pointers
• Structures
• File I/O

Basic Syntax

The basic syntax of C programs consists of functions and variables. A simple C program looks like this:

#include <stdio.h>

int main() {
    printf("Hello, World!");
    return 0;
}
    

Data Types

C supports various data types including int, float, char, and more. Here are some examples:

int integer = 10;
float floating_point = 3.14;
char character = 'A';
    

Control Structures

C supports various control structures like if-else, for loop, while loop, etc. Here are some examples:

// If-Else
if (integer > 5) {
    printf("Integer is greater than 5");
} else {
    printf("Integer is less than or equal to 5");
}

// For Loop
for (int i = 0; i < 10; i++) {
    printf("%d ", i);
}
    

Functions

Functions in C allow you to divide your code into modular blocks. Here is an example:

void printMessage() {
    printf("Hello from a function!");
}

int main() {
    printMessage();
    return 0;
}
    

Arrays

Arrays in C are used to store multiple values of the same type. Here is an example:

int numbers[5] = {1, 2, 3, 4, 5};

for (int i = 0; i < 5; i++) {
    printf("%d ", numbers[i]);
}
    

Pointers

Pointers are a powerful feature in C that allows you to work with memory directly. Here is an example:

int value = 10;
int *pointer = &value;

printf("Value: %d, Pointer: %p", value, pointer);
    

Structures

Structures in C allow you to group different data types together. Here is an example:

struct Person {
    char name[50];
    int age;
};

struct Person person1;

person1.age = 30;
strcpy(person1.name, "John Doe");

printf("Name: %s, Age: %d", person1.name, person1.age);
    

File I/O

C provides functions to work with files. Here is an example of reading a file:

FILE *file;
file = fopen("example.txt", "r");

if (file) {
    char line[100];
    while (fgets(line, sizeof(line), file)) {
        printf("%s", line);
    }
    fclose(file);
}