initialise a vector in c++ code example

Example 1: initialize vector of vector c++

#include <iostream>
#include <vector>
 
#define M 3
#define N 4
 
int main()
{
  // specify default value to fill the vector elements
  int default_value = 1;
  // first initialize a vector of ints with given default value
  std::vector<int> v(N, default_value);
  // Use above vector to initialize the two-dimensional vector
  std::vector<std::vector<int>> matrix(M, v);
  
  return 0;
}

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

// First include the vector library:
#include <vector>

// The syntax to create a vector looks like this:
std::vector<type> name;

// We can create & initialize "lol" vector with specific values:
std::vector<double> lol = {66.666, -420.69};

// it would look like this: 66.666 | -420.69

Example 3: how to initialize vector in c++ with all elements 0

vector<int> arr(10,0);

Example 4: c++ initialize a vector

#include <bits/stdc++.h> 
#include <vector> 
using namespace std; 
  
int main() 
{ 
// This vector initializes with the values: 10, 20, and 30
  vector<int> vect{ 10, 20, 30 }; 

    return 0; 
}

Example 5: how to initialize vector

vector<int> vect{ 10, 20, 30 };