C++ Exercises: Create a new string using the first and last n characters from a given string of length at least n

Last update on April 07 2025 12:57:54 (UTC/GMT +8 hours)

First and Last n Characters from String

Write a C++ program to create a new string using the first and last n characters from a given string of length at least n.

Sample Solution:

C++ Code :

#include <iostream> // Including the input/output stream library

using namespace std; // Using the standard namespace

// Function that concatenates substrings based on the given indices
string test(string s1, int n)
{
    return s1.substr(0, n) + s1.substr(s1.length() - n); // Concatenate a substring from index 0 to n and a substring from length-n to the end of s1
}

// Main function
int main() 
{
    cout << test("Hello", 1) << endl;   // Output the result of test function with "Hello" and n=1
    cout << test("Python", 2) << endl;  // Output the result of test function with "Python" and n=2
    cout << test("on", 1) << endl;      // Output the result of test function with "on" and n=1
    cout << test("o", 1) << endl;       // Output the result of test function with "o" and n=1
    return 0;    // Return statement indicating successful termination of the program
}

Sample Output:

Ho
Pyon
on
oo

Visual Presentation:

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C++ program to read a string and an integer n, then output a new string made by concatenating the first n and last n characters of the input.
• Write a C++ program that extracts the first and last n characters from a given string and joins them into a single output string.
• Write a C++ program to combine the first n and last n letters of an input string and display the resultant string.
• Write a C++ program that accepts a string and a number n, then prints the concatenation of its leading and trailing n characters.

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