C++ concatenate two int arrays into one larger array

Question

Is there a way to take two int arrays in C++

int * arr1; int * arr2; //pretend that in the lines below, we fill these two arrays with different //int values 

and then combine them into one larger array that contains both arrays' values?

Answer 1

int * result = new int[size1 + size2]; std::copy(arr1, arr1 + size1, result); std::copy(arr2, arr2 + size2, result + size1); 

Just suggestion, vector will do better as a dynamic array rather than pointer

Answer 2

If you're using arrays, you need to allocate a new array large enough to store all of the values, then copy the values into the arrays. This would require knowing the array sizes, etc.

If you use std::vector instead of arrays (which has other benefits), this becomes simpler:

std::vector<int> results; results.reserve(arr1.size() + arr2.size()); results.insert(results.end(), arr1.begin(), arr1.end()); results.insert(results.end(), arr2.begin(), arr2.end());