# Converting Strings

In C programming, converting strings often involves changing the representation of data, such as converting a string to an integer or vice versa. Let's explore common string conversion operations in C.

## 1. String to Integer Conversion

Converting a string to an integer can be achieved using the `atoi` (ASCII to Integer) function from the `<stdlib.h>` library.

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

int main() {
    const char *numberString = "123";
    
    // Convert string to integer
    int convertedNumber = atoi(numberString);
    
    printf("Converted Number: %d\n", convertedNumber);

    return 0;
}
```

This program converts the string "123" to an integer using `atoi` and prints the result.

## 2. Integer to String Conversion

Converting an integer to a string can be done using the `sprintf` (String Print Formatted) function.

```c
#include <stdio.h>

int main() {
    int number = 456;
    char resultString[10]; // Sufficient size to hold the string representation
    
    // Convert integer to string
    sprintf(resultString, "%d", number);
    
    printf("Converted String: %s\n", resultString);

    return 0;
}
```

This program converts the integer `456` to a string using `sprintf` and prints the result.

## 3. String to Double Conversion

Converting a string to a double can be done using the `atof` (ASCII to Float) function from the `<stdlib.h>` library.

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

int main() {
    const char *doubleString = "123.45";
    
    // Convert string to double
    double convertedDouble = atof(doubleString);
    
    printf("Converted Double: %lf\n", convertedDouble);

    return 0;
}
```

This program converts the string "123.45" to a double using `atof` and prints the result.

## 4. Double to String Conversion

Converting a double to a string can be done using the `sprintf` function as well.

```c
#include <stdio.h>

int main() {
    double pi = 3.14159;
    char resultString[20]; // Sufficient size to hold the string representation
    
    // Convert double to string
    sprintf(resultString, "%.2lf", pi);
    
    printf("Converted String: %s\n", resultString);

    return 0;
}
```

This program converts the double `3.14159` to a string with two decimal places using `sprintf` and prints the result.

Understanding these conversion techniques is crucial for handling various types of data in C programming.

If you have specific questions or if there are additional topics you'd like to explore, feel free to ask!
