# Practices

**1. Mini Projects**

**1.1. Simple Calculator**

A basic calculator that performs addition, subtraction, multiplication, and division.

**Features:**

* Accepts two numbers and an operator from the user.
* Performs the chosen operation.
* Displays the result.

**Example Code:**

```c
#include <stdio.h>

int main() {
    char operator;
    double num1, num2, result;

    // User input
    printf("Enter an operator (+, -, *, /): ");
    scanf(" %c", &operator);
    printf("Enter two numbers: ");
    scanf("%lf %lf", &num1, &num2);

    // Calculation and result display
    switch (operator) {
        case '+':
            result = num1 + num2;
            break;
        case '-':
            result = num1 - num2;
            break;
        case '*':
            result = num1 * num2;
            break;
        case '/':
            if (num2 != 0)
                result = num1 / num2;
            else
                printf("Error! Division by zero.\n");
            return 1;
        default:
            printf("Error! Operator is not correct.\n");
            return 1;
    }

    printf("%.2lf %c %.2lf = %.2lf\n", num1, operator, num2, result);
    return 0;
}
```

**1.2. File Reader**

A program to read and display the contents of a file.

**Features:**

* Opens a file specified by the user.
* Reads its content and prints it to the screen.
* Handles errors if the file cannot be opened.

**Example Code:**

```c
#include <stdio.h>

int main() {
    FILE *file;
    char filename[100];
    char ch;

    printf("Enter the filename: ");
    scanf("%s", filename);

    file = fopen(filename, "r");
    if (file == NULL) {
        printf("Error! Could not open file.\n");
        return 1;
    }

    printf("Contents of %s:\n", filename);
    while ((ch = fgetc(file)) != EOF) {
        putchar(ch);
    }

    fclose(file);
    return 0;
}
```

**1.3. Number Guessing Game**

A simple game where the user guesses a number between 1 and 100.

**Features:**

* Generates a random number.
* Allows the user to guess the number.
* Provides feedback on whether the guess is too high or too low.

**Example Code:**

```c
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main() {
    int number, guess, attempts = 0;

    // Initialize random seed
    srand(time(0));

    // Generate a random number between 1 and 100
    number = rand() % 100 + 1;

    // Game loop
    do {
        printf("Guess the number (1 to 100): ");
        scanf("%d", &guess);
        attempts++;

        if (guess > number)
            printf("Too high! Try again.\n");
        else if (guess < number)
            printf("Too low! Try again.\n");
        else
            printf("Congratulations! You guessed the number in %d attempts.\n", attempts);
    } while (guess != number);

    return 0;
}
```

***

#### **2. Solving Real-World Problems**

**2.1. To-Do List Application**

A program to manage a list of tasks.

**Features:**

* Add tasks.
* List tasks.
* Mark tasks as completed.

**Example Code:**

This one can get a bit complex, so start with a simple version and expand as you become more comfortable with file handling and data structures.

**2.2. Budget Tracker**

A simple program to track income and expenses.

**Features:**

* Add income and expenses.
* Calculate and display the total balance.

**Example Code:**

```c
#include <stdio.h>

int main() {
    float income = 0, expenses = 0, balance;

    printf("Enter your total income: ");
    scanf("%f", &income);

    printf("Enter your total expenses: ");
    scanf("%f", &expenses);

    balance = income - expenses;

    printf("Your balance is: %.2f\n", balance);

    return 0;
}
```

***

#### **3. Practice Tips**

1. **Start Small**: Begin with simple projects and gradually move to more complex ones as you become more comfortable with the language.
2. **Read Documentation**: Familiarize yourself with the C Standard Library functions and use them to make your code more efficient and powerful.
3. **Debug Regularly**: Use GDB or other debugging tools to troubleshoot issues and understand how your code executes.
4. **Optimize Gradually**: Focus on writing correct code first, then work on optimizing for performance and memory usage.
5. **Collaborate and Share**: Share your projects with others, get feedback, and work on collaborative projects to learn from different perspectives.


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