C++ How To Merge Two Arrays

Merge Two Arrays

Copy the elements of both arrays into a new, larger array:

int first[] = {1, 2, 3};
int second[] = {4, 5, 6};
int merged[6];

for (int i = 0; i < 3; i++) {
  merged[i] = first[i];
  merged[i + 3] = second[i];
}

for (int num : merged) {
  cout << num << " ";
}

With vectors, you do not need to know the size in advance. Use insert() to add all elements of one vector to the end of another:

vector<int> first = {1, 2, 3};
vector<int> second = {4, 5, 6};

vector<int> merged = first;
merged.insert(merged.end(), second.begin(), second.end());

for (int num : merged) {
  cout << num << " ";
}

Explanation:
In the first example, the elements of second are placed after the elements of first, starting at position 3.
In the second example, merged starts as a copy of first, and insert() adds the elements of second at the end.

Related Pages

C++ Arrays Tutorial

C++ Vectors Tutorial