Merge Arrays in C++

Merge two arrays into one in C++.

BeginnerArray ProgramsExample 3 of 4

merge-arrays.cpp

1#include <iostream>
2using namespace std;
3
4int main() {
5    int n1, n2;
6    
7    cout << "Enter size of first array: ";
8    cin >> n1;
9    int arr1[n1];
10    cout << "Enter " << n1 << " elements: ";
11    for (int i = 0; i < n1; i++) {
12        cin >> arr1[i];
13    }
14    
15    cout << "Enter size of second array: ";
16    cin >> n2;
17    int arr2[n2];
18    cout << "Enter " << n2 << " elements: ";
19    for (int i = 0; i < n2; i++) {
20        cin >> arr2[i];
21    }
22    
23    int merged[n1 + n2];
24    
25    // Copy first array
26    for (int i = 0; i < n1; i++) {
27        merged[i] = arr1[i];
28    }
29    
30    // Copy second array
31    for (int i = 0; i < n2; i++) {
32        merged[n1 + i] = arr2[i];
33    }
34    
35    cout << "Merged array: ";
36    for (int i = 0; i < n1 + n2; i++) {
37        cout << merged[i] << " ";
38    }
39    cout << endl;
40    
41    return 0;
42}

Output

Enter size of first array: 3
Enter 3 elements: 1 2 3
Enter size of second array: 3
Enter 3 elements: 4 5 6
Merged array: 1 2 3 4 5 6

What's going on

Merging arrays involves combining two arrays into one. We create a new array of size (n1 + n2). First, we copy all elements from the first array, then copy all elements from the second array starting at index n1.

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