c

C Language Tutorial

1. What is C?

C is a general-purpose, procedural programming language. It is known for its efficiency and is widely used for system programming, developing operating systems, embedded systems, and applications.

2. How to Install a C Compiler?

1. Download a C compiler like GCC (GNU Compiler Collection) or an IDE such as Code::Blocks, Dev-C++, or Visual Studio.
2. Install the compiler or IDE by following the setup instructions.
3. Verify the installation by running gcc --version in the terminal (if using GCC).

3. Your First C Program

Let’s write our first C program:

#include <stdio.h>

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

Save this code in a file named hello.c, then compile and run it:

• To compile: gcc hello.c -o hello
• To run: ./hello

4. Variables and Data Types

In C, variables are declared with specific data types. Here are some common data types:

#include <stdio.h>

int main() {
    int x = 10;       // Integer
    float y = 3.14;   // Float
    char name = 'A';  // Character
    printf("x = %d, y = %.2f, name = %c
", x, y, name);
    return 0;
}

5. Conditional Statements

Conditional statements in C include if, else if, and else.

#include <stdio.h>

int main() {
    int num = 10;
    if (num > 0) {
        printf("Positive number
");
    } else if (num == 0) {
        printf("Zero
");
    } else {
        printf("Negative number
");
    }
    return 0;
}

6. Loops

C supports for, while, and do-while loops.

For Loop:

#include <stdio.h>

int main() {
    for (int i = 0; i < 5; i++) {
        printf("%d
", i);
    }
    return 0;
}

While Loop:

#include <stdio.h>

int main() {
    int count = 0;
    while (count < 5) {
        printf("%d
", count);
        count++;
    }
    return 0;
}

7. Functions

Functions in C help to modularize code.

#include <stdio.h>

void greet(char name[]) {
    printf("Hello, %s!
", name);
}

int main() {
    greet("Alice");
    return 0;
}

8. Arrays

Arrays in C are used to store multiple values of the same data type.

#include <stdio.h>

int main() {
    int numbers[] = {1, 2, 3, 4, 5};
    for (int i = 0; i < 5; i++) {
        printf("%d
", numbers[i]);
    }
    return 0;
}

9. Structures

Structures in C allow grouping of variables of different data types.

#include <stdio.h>

struct Student {
    char name[50];
    int age;
    float marks;
};

int main() {
    struct Student s1 = {"John", 21, 85.5};
    printf("Name: %s, Age: %d, Marks: %.2f
", s1.name, s1.age, s1.marks);
    return 0;
}

10. File Handling

File handling in C is done using FILE pointers.

#include <stdio.h>

int main() {
    FILE *file = fopen("example.txt", "w");
    fprintf(file, "Hello, C Language!
");
    fclose(file);

    file = fopen("example.txt", "r");
    char buffer[100];
    fgets(buffer, 100, file);
    printf("%s", buffer);
    fclose(file);

    return 0;
}

11. Pointers

Pointers in C store the memory address of a variable.

#include <stdio.h>

int main() {
    int num = 10;
    int *ptr = #
    printf("Value: %d, Address: %p
", *ptr, ptr);
    return 0;
}

12. C Libraries

C has a variety of libraries to simplify development. Some commonly used libraries are:

• stdio.h: For input/output operations.
• stdlib.h: For memory management and conversions.
• string.h: For string manipulation.
• math.h: For mathematical computations.