C++ Program to Reverse a Given String

This page contains a C++ program that reverses a given string. The program uses basic string manipulation techniques to achieve this task.

Program Explanation

The C++ program to reverse a string follows these steps:

1. Include necessary headers: Use the #include directive to include required libraries.
2. Main Function: The main function is the entry point of the program.
3. Input String: Define a string that you want to reverse.
4. Reverse the String: Use a loop to reverse the string by swapping characters from the beginning and end.
5. Print the Result: Output the reversed string to the console.

C++ Program Code

#include <iostream>
#include <string>

/**
 * Function to reverse a given string.
 * @param str the string to be reversed
 * @return the reversed string
 */
std::string reverseString(const std::string &str) {
    std::string reversed = str;
    int n = reversed.length();

    // Swap characters from the beginning and end
    for (int i = 0; i < n / 2; ++i) {
        std::swap(reversed[i], reversed[n - i - 1]);
    }

    return reversed;
}

/**
 * Main function which is the entry point of the program.
 */
int main() {
    // Define the string to be reversed
    std::string original = "Hello, World!";
    
    // Call the reverse function and store the result
    std::string reversed = reverseString(original);
    
    // Print the original and reversed strings
    std::cout << "Original String: " << original << std::endl;
    std::cout << "Reversed String: " << reversed << std::endl;

    return 0;
}

Program Details

The program contains the following components:

• reverseString Function: A function that takes a string as input, reverses it by swapping characters, and returns the reversed string.
• main Function: The entry point of the program where the string is defined and the reverse function is called.

Running the Program

To run the program:

1. Save the code in a file named ReverseString.cpp.
2. Compile the program using the command: g++ -o ReverseString ReverseString.cpp.
3. Run the compiled program using the command: ./ReverseString.

Explanation of the C++ Program:

1. Include Headers:
   • #include <iostream>: For input and output operations.
   • #include <string>: For string operations.
2. reverseString Function:
   • Takes a const std::string &str as input and returns a reversed string.
   • Creates a copy of the input string to reverse it.
   • Uses a loop to swap characters from the beginning and end of the string until the middle of the string is reached.
3. Main Function:
   • Initializes a string original with a value to be reversed.
   • Calls the reverseString function and stores the result in reversed.
   • Prints both the original and reversed strings to the console.