C++ Exercises: New array from an existing array

Last update on April 07 2025 12:57:30 (UTC/GMT +8 hours)

Create Array of First n Strings from Array

Write a C++ program to create an array using the first n strings from a given array of strings. (n>=1 and <=length of the array).

Test Data:
({"a", "b", "bb", "c", "ccc" }, 2) -> {"a", "b"}
({"a", "b", "bb", "c", "ccc" }, 3) -> {"a", "b", "bb"}

Sample Solution:

C++ Code :

#include <iostream>  // Including input-output stream header file
#include<string.h>   // Including string manipulation header file

using namespace std;  // Using standard namespace

string *new_array;  // Declaring a pointer for the new string array

// Function to create a new string array and copy elements from the original array
string *test(string *text, int n) {
    new_array = new string[n];  // Creating a new string array of size 'n'

    // Loop to copy elements from the original array 'text' to the new array 'new_array'
    for(int i = 0; i < n; i++) {
        new_array[i] = text[i];  // Copying each element from 'text' to 'new_array'
    }

    return new_array;  // Returning the pointer to the new string array
}

// Main function
int main() {
    string text[] = {"a", "b", "bb", "c", "ccc"};  // Original array of strings

    string* result_array;  // Pointer to store the returned new string array

    int arr_length = sizeof(text) / sizeof(text[0]);  // Calculating the length of the original array
    cout << "Original array elements: " << endl;

    // Displaying the original array elements
    for (int i = 0; i < arr_length; i++) {
        std::cout << text[i] << ' ';
    }

    int n = 2;  // Size of the new array
    result_array = test(text, n);  // Calling 'test' function to create a new array of size 'n'

    // Displaying the new array with size 'n'
    cout << "\n\nNew array with size " << n << endl;
    for(int i = 0; i < n; i++) {
        std::cout << result_array[i] << ' ';
    }

    n = 4;  // Changing the size of the new array
    result_array = test(text, n);  // Calling 'test' function again with a different size

    // Displaying the new array with size 'n'
    cout << "\n\nNew array with size " << n << endl;
    for(int i = 0; i < n; i++) {
        std::cout << result_array[i] << ' ';
    }

    delete [] new_array;  // Deleting the allocated memory for the new array

    return 0;  // Returning 0 to indicate successful completion of the program
}

Sample Output:

Original array elements: 
a b bb c ccc 

New array with size 2
a b 

New array with size 4
a b bb c

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program to create a new array containing the first n strings from an existing string array.
Write a C++ program that reads an array of strings and an integer n, then outputs an array of the first n strings.
Write a C++ program to extract the initial n elements from a string array and display them as a new array.
Write a C++ program that processes a string array and returns a subarray composed of its first n entries, where n is provided by the user.

C++ Code Editor:

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