C++ Exercises: Create a new string where 'if' is added to the front of a given string

Last update on April 07 2025 12:58:22 (UTC/GMT +8 hours)

Add 'if' to String

Write a C++ program to create a string where 'if' is added to the front of a given string. If the string already begins with 'if', return the string unchanged.

Sample Solution:

C++ Code :

#include <iostream>

using namespace std;

// Function to modify a string based on certain conditions
string test(string s)
{
    // Check if the string length is greater than 2 and if the substring from index 0 to 1 (first two characters) is "if"
    if (s.length() > 2 && s.substr(0, 2) == "if")
    {
        return s; // Return the string as it is if it starts with "if" and has a length greater than 2
    }
    return "if " + s; // Prepend "if " to the string if it doesn't start with "if" or has a length less than or equal to 2
}

// Main function
int main() 
{
    cout << test("if else") << endl;  // Output the result of test function with argument "if else"
    cout << test("else") << endl;    // Output the result of test function with argument "else"
    return 0;    // Return 0 to indicate successful execution of the program
}

Sample Output:

if else
if else

Visual Presentation:

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C++ program that prepends "if" to a string unless the string already begins with "if", in which case it returns the string unchanged.
• Write a C++ program to check if a given string starts with "if"; if not, add "if" at the beginning and print the modified string.
• Write a C++ program that reads a string and conditionally concatenates "if" to its start only if it isn’t already prefixed by "if".
• Write a C++ program that accepts a string, examines its first two characters, and adds "if" to the front if they do not match "if".

C++ Code Editor:

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