define vector with size c++ code example

Example 1: how to initialize vector in c++ with all elements 0

vector<int> arr(10,0);

Example 2: how to initialize a vector in c++

std::vector<type> name;

Example 3: c++ create vector of size

// create a vector with 20 integer elements
std::vector<int> arr(20);

for(int x = 0; x < 20; ++x)
   arr[x] = x;