C++ Exercises: Create a new string from a given string after swapping last two characters

Last update on August 13 2025 12:46:54 (UTC/GMT +8 hours)

Swap Last Two Characters

Write a C++ program to create a new string from a given string after swapping the last two characters.

Sample Solution:

C++ Code :

#include <iostream> // Including the input/output stream library
using namespace std; // Using the standard namespace

// Function that performs manipulation on the input string
string test(string s1)
{
    // Check if the length of the string is greater than 1
    if (s1.length() > 1)
    {
        // Return a modified string formed by rearranging characters:
        // Substring from index 0 to length-2 (excluding last two characters)
        // Last character of the original string
        // Second-to-last character of the original string
        return s1.substr(0, s1.length() - 2) + s1[s1.length() - 1] + s1[s1.length() - 2];
    }
    else
    {
        // Return the original string if its length is 1 or less
        return s1;
    }
}

// Main function
int main() 
{
    // Output the results of test function with different input strings
    cout << test("Hello") << endl;   // Output for "Hello"
    cout << test("Python") << endl;  // Output for "Python"
    cout << test("PHP") << endl;     // Output for "PHP"
    cout << test("JS") << endl;      // Output for "JS"
    cout << test("C") << endl;       // Output for "C"
    return 0;    // Return statement indicating successful termination of the program
}

Sample Output:

Helol
Pythno
PPH
SJ
C

Visual Presentation:

C++ Basic Algorithm Exercises: Create a new string from a given string after swapping last two characters.

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program that reads a string and swaps its last two characters, handling cases where the string length is less than 2 by returning the original string.
Write a C++ program to exchange the positions of the final two characters of an input string, ensuring proper handling of short strings.
Write a C++ program that takes a string input and outputs a new string with the last two characters interchanged; if the string length is one, print it as is.
Write a C++ program to reverse the order of the final two letters of a string and print the modified string, leaving strings of insufficient length unchanged.

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